From government surveillance programs to microchips in vaccines, technology-centric conspiracy theories have exploded in the digital age, adding to some of the best conspiracy theories already in existence.

While most probably seem laughable to the technically literate, some of these theories have spread like wildfire and had significant real-world impacts. And although most are complete fabrications, some do contain a kernel of truth — and others have turned out to be eerily accurate. Here's a rundown of some of the most pernicious technology conspiracy theories.

The Large Hadron Collider is opening a portal to hell

Verdict: Not True

The Large Hadron Collider, operated by the European Organization for Nuclear Research (CERN) in Switzerland, has been an obsession with conspiracy theorists almost since its opening in 2008. The organization has even seen it necessary to have a dedicated page on its website responding to some of the more outlandish claims.

One of the most persistent fears is that the machine could create a black hole that would consume Earth or open portals to other dimensions. At their most hysterical, these theories have suggested that researchers are deliberately opening the gates of Hell to communicate with demonic entities.

Unsurprisingly, physicists swiftly debunked these ideas. The collider uses magnetic fields to accelerate protons to extremely high speeds before smashing them together to create smaller particles. The goal is to discover new elementary particles that could help test theories about how the Universe works.

Creating even a microscopic black hole or wormhole would require an accelerator the size of the whole universe, say researchers. It would also decay in a fraction of a second thanks to Hawking radiation, which causes black holes to lose mass and eventually evaporate. Even if such a black hole was stable, which current physics suggests is impossible, it would take three trillion years to consume just one kilogram of matter.

Tracking microchips in COVID-19 vaccines

Verdict: Not True

When the COVID-19 pandemic hit in early 2020, governments took unprecedented steps to control its spread, including lockdowns and vaccine mandates. That proved fertile breeding ground for novel conspiracy theories, including the bizarre claim that authorities were sneaking microchips into vaccines so they could track people.

The theory’s origins can be traced to March 2020, when Bill Gates participated in a Reddit discussion about digital health passports. A Swedish website dedicated to biohacking misinterpreted his comments and published an article saying the billionaire wanted to use microchip implants to fight the pandemic.

Via a paranoid game of Telephone, this slowly morphed into the idea that the government was using the vaccine to implant tracking chips in citizens. Needless to say, the theory is nonsense. There is no evidence that any of the billions of people vaccinated against COVID-19 have been implanted with tracking hardware.

But by January 2021, one in 10 American adults believed the theory. More worryingly, a poll found that one in four Americans said they were uncertain whether vaccines contained microchips. The conspiracy was built on years of anti-vaccine disinformation, and further fuelled the vaccine hesitancy that made it so hard to control the pandemic.

5G networks spread COVID-19

Verdict: Not True

Another COVID-19 related conspiracy theory that gained significant traction claimed that the disease was being spread by newly installed 5G cellular networks. The theory became so widespread that cell towers were set on fire in several countries, and social media platforms were forced to actively combat its spread.

The idea is firmly contradicted by the overwhelming evidence that COVID-19 is caused by a contagious virus. And crucially, the virus spread rapidly in areas with no 5G coverage whatsoever. Nonetheless, the U.S. Federal Emergency Management Agency felt compelled to issue a statement clarifying that 5G technology does not cause coronavirus, while U.K. government officials dismissed it as a "crackpot conspiracy.”

The fears likely built on top of existing concerns about the health impacts of radiation from cellphone towers. But there is no credible evidence that existing technology causes health problems, and 5G should raise even fewer concerns. The radio frequency waves used by these networks are forms of non-ionizing radiation, meaning they lack the energy to damage DNA or cells in ways that could cause disease. High-band 5G uses millimetre wave frequencies that cannot even penetrate human skin.

The dead internet theory

Verdict: Partially True

The dead internet theory proposes that the web is now dominated by bots interacting with each other with minimal human involvement. The idea has been around for several years, but has been further fuelled by the recent rise of artificial intelligence (AI) chatbots and agents.

The conspiracy first surfaced in 2021 on the Agora Road's Macintosh Cafe forum, in a thread titled "Dead Internet Theory: Most Of The Internet Is Fake." The idea is that automated systems are being used to craft content designed to draw engagement and generate ad revenue. But the theory suggests that those interacting with this content are also bots.

While the extent to which this is true is debatable, there is an element of truth to the theory. Studies show bot traffic was responsible for 51% of all internet activity in 2024 — the first time bots surpassed humans. And since ChatGPT's launch, AI-generated content has exploded, with another study finding that 13.1% of websites now host such material.

This is leading to fears that the internet is being rapidly flooded with low-quality "AI slop" that could degrade its usefulness over time. Given that OpenAI CEO Sam Altman recently gave credence to the theory, this might be one to start taking more seriously. The evolution of this idea, fueled by AI, might permanently change how we use the internet in the years to come.

Governments can control the weather

Verdict: Partially True

Following the highly destructive hurricanes Helene and Milton in 2024, rumours swirled that they were the result of government weather control programs. One of the most prominent boosters of the theory was U.S. Congresswoman Marjorie Taylor Greene, who tweeted “Yes they can control the weather” to her 1.2 million followers shortly before Hurricane Milton hit.

While these specific claims are patently false, like many good conspiracy theories, they contain a kernel of truth. The U.S. government had been interested in weather control as far back as 1891 and had a serious "weather weapons" program in the form of Operation Popeye between 1967 and 1972 during the Vietnam War. Such practices were banned by the Environmental Modification Treaty in 1977.

Basic forms of weather modification also exist today, in particular cloud seeding. This involves dispersing materials like silver iodide into clouds, which can marginally enhance rainfall. Countries like China and Saudi Arabia use the approach to assist in agriculture. China harnessed this technology to ensure clear skies for the 2008 Olympics.

Proposals to fight climate change via solar geoengineering have also further fuelled conspiracy theories. This would involve spreading tiny particles in the upper atmosphere to reflect sunlight. But these approaches are a long way from the kind of weaponized weather control conspiracists dream of.

Phones eavesdrop on you for ad targeting

Verdict: Partially True

Many people have had the eerie experience of seeing ads for products appearing on their phone shortly after discussing them offline. This has led to a persistent belief that smartphones secretly listen to our conversations for advertising purposes.

The rumour has been around for decades, but Instagram head Adam Mosseri recently felt compelled to address it directly, stating the company doesn't use microphones this way and calling it a "gross violation of privacy." Multiple studies have also found no evidence of covert audio recording, and there are several reasons why it would be impractical.

For a start, constant audio recording would rapidly drain phone batteries and trigger visible indicators on phone displays. More importantly, unauthorized recording would create enormous legal liability for those who engaged in it.

But there is something potentially more unsettling behind the phenomenon. Online platforms, advertisers and data brokers are constantly collecting, curating and reselling every tiny piece of information they can glean from our online and offline behaviour. This allows them to develop incredibly accurate profiles of people to provide spookily appropriate, and timely, product suggestions.

Planned obsolescence

Verdict: Partially True

From clothes to consumer electronics and even cars, people increasingly complain that products don’t last as long as they used to. The theory of Planned Obsolescence suggests that this is no accident, and companies deliberately design products with short lifespans to force repeat purchases.

The idea has circulated for a long time and has some truth to it. There is historical evidence that companies have pursued obsolescence as a strategy — in the 1920s, for instance, major light bulb manufacturers came together to form the "Phoebus cartel," which colluded to reduce bulb lifespans to just 1,000 hours. General Motors also pioneered annual model changes to entice customers to buy newer vehicles, creating a template that other industries copied. Technology vendors are particularly guilty — think smartphones with batteries that degrade in just a few years, or no longer support software updates.

But the practice isn't necessarily aimed at tricking us into buying more than we need. Rapid product turnover makes things cheaper to manufacture and with technology in particular, consumers prefer paying less upfront for devices they'll replace soon to access new features. Durability comes at a price too, so customers are often happy to have cheaper products that may not last as long — for instance, clothes that children will grow out of.

Government-sponsored mind control programs

Verdict: True

There is a whole menagerie of conspiracy theories speculating that the government uses technology and drugs for mind control. One prominent recent example is the claim that the U.S. military’s High-frequency Active Auroral Research Program (HAARP) is secretly using radio waves to manipulate people’s thoughts.

While that specific claim has been firmly debunked, the idea that the U.S. government is attempting to control people’s minds is not so outlandish. In 1953, CIA director Allen Dulles launched a top secret program called MKUltra aimed at developing exactly those kinds of capabilities. The agency covertly contracted out 162 projects to various universities, research foundations and institutions to study how psychoactive drugs, hypnosis, electroshock therapy, sensory deprivation and various forms of torture could be used to manipulate people’s mental states.

Experiments were carried out on both volunteers and unwitting subjects, including prisoners, sex workers, soldiers and children. By the mid-1960s, the project’s backers concluded that while it was easy to dismantle a human mind, subsequently seizing control of it was beyond them, and they wound down research in 1964.

Investigative reporting by the New York Times uncovered the project in 1974 and led to a series of congressional hearings. But the bulk of documents related to the project had been destroyed the year before, meaning the true extent of the program remains a mystery.

Widespread digital surveillance

Verdict: True

Paranoia around the government’s ability to listen in on our phone calls or online communications is a defining feature of many conspiracy theories. But in June 2013, former CIA contractor Edward Snowden leaked a treasure trove of classified documents to journalists that validated many of these fears.

The revelations uncovered a mass surveillance network operated by U.S. intelligence agencies and their foreign allies to collect phone records and monitor internet activity across the globe. Most prominently, it uncovered the PRISM program, operated by the U.S. National Security Agency (NSA), which used secret court orders to demand internet communication data from technology companies.

The U.K.'s Government Communications Headquarters (GCHQ) was also revealed to be tapping into 200 fiber-optic cables around the world, allowing it to monitor up to 600 million communications daily.

The reports lead to widespread outrage because the surveillance targeted not only suspected terrorists and criminals but also ordinary citizens, journalists, corporations and 35 foreign leaders – most notably the phone of the German chancellor at the time, Angela Merkel. But despite an initial public outcry, Congress renewed many of these surveillance programs in 2018 with little debate, suggesting that widespread government surveillance remains alive and well.

Test your knowledge of unfounded beliefs, from flat Earth to lizard people with our conspiracy theory quiz!

The winners of the 2026 Milky Way Photographer of the Year contest are here — and they are stunning. Each image captures a different angle of our galaxy's center, showing the complex mixture of gases and stars that forms our cosmic home.

The contest was established in 2018 by photographer Dan Zafra to highlight the different facets of the Milky Way galaxy. While this year's winners include a variety of images from across the globe — from New Zealand to Yellowstone National Park — they all had one thing in common: an appreciation for the universe around us.

Here, we present a handful of our favorite honorees that capture the magic of the Milky Way. (And if you want to try your own hand at it, here are some beginning tips for taking breathtaking photos of our galaxy this summer).

"Geminid Symphony Over La Palma's Guardian of the Sky"

Photographer: Uroš Fink

Location: Roque de los Muchachos Observatory; La Palma​, Spain

This panorama captures the Geminid meteor shower in the skies over La Palma​, one of Spain's Canary Islands. La Palma is home to the Gran Telescopio Canarias, the largest optical telescope in the world. Also captured in this image is the Gum Nebula, found between the southern constellations Vela and Puppis.

"Galactic Gandalf"

Photographer: Evan McKay

Location: Wairarapa Coast, New Zealand​

Leaning on New Zealand's reputation for being where much of the "Lord of the Rings" series was filmed, photographer Evan McKay reveals a stunning night sky enjoyed by the wizard Gandalf, added in later.

"When I first discovered this location, I immediately envisioned creating something special beneath the night sky," McKay said in a statement. "Given the complexity of the scene, I knew the final image would require a significant amount of work. Over the following weeks, starting in November, I returned whenever possible to collect the necessary data for this panorama, carefully building the image piece by piece under the night sky."

"Sodium Milky Way"

Photographer: Julien Looten

Location: Very Large Telescope; Paranal, Chile​

Chile's Atacama Desert hosts many different telescopes, including the Very Large Telescope (VLT) on Mount Paranal. There, the high altitude and dry desert air make observing the night sky much easier than in areas with lots of city lights.

In this image, both the Large and Small Magellanic Clouds — dwarf galaxies that orbit close to the Milky Way — can be seen toward the left.

"Subtle airglow adds another layer to the scene, a natural emission produced by chemical reactions in the upper atmosphere at altitudes of 80 to 100 kilometers [50 to 62 miles]," Looten said in the statement. "In this image, it reveals a range of colors, with green tones on the left and warmer reddish hues toward the right."

In the foreground, one of the VLT's telescopes shoots four sodium laser beams into the sky, creating four guide stars that astronomers can use to calibrate the observation systems.

"Firewater"

Photographer: Baillie Farley

Location: Grand Prismatic Spring, Yellowstone National Park, Wyoming

Like the VLT image, this photo of our home galaxy above Yellowstone National Park has a subtle airglow to it. It also captures the colorful Grand Prismatic Spring, a 121-foot-deep (36.8 meters) hot spring whose bacteria give the spring its colorful appearance.

• Read our full review of the Sony A7 III, which Baillie used to capture this image

"Perseid Meteors Over Durdle Door"

Photographer: Josh Dury

Location: Durdle Door; Dorset, England

Astrophotographer Josh Dury is known for his stunning night-sky images, and this one does not disappoint. The long-exposure photo captures the streaks of meteors from the Perseid meteor shower, which happens annually from mid-July to late August as debris from Comet Swift-Tuttle moves across Earth's atmosphere.

"'Ancient fireworks' from Comet Swift-Tuttle hurtled through the atmosphere to document this ultra-wide angle composite image above the natural limestone arch of Durdle Door," Dury said in the statement. "In the foreground, a singular glow worm was documented amongst reeds along the sea cliff edge."

• Read our full review of the Sony A7S III, which Josh used to capture this image

"Galaxy on the Rise"

Photographer: Anastasia Gulova

Location: Tenerife, Spain

It took over four hours for photographer Anastasia Gulova to find the perfect place to document the Milky Way's beauty from inside a cave on Tenerife in Spain's Canary Islands.

"Capturing the image proved just as challenging," Gulova said. "Composing and shooting the panoramic foreground required careful positioning, while properly illuminating the upper section of the cave was particularly difficult. To manage this, I used focus stacking across different planes, including the upper edge, the horizon, and the lower foreground, all in near-total darkness, where the brief blue hour offered little assistance."

Gulova's persistence was worth it, as she snapped the brilliant colors of the Milky Way mixed with the night sky and beginning sunrise.

• Read our full review of the Canon EOS R5, which Anastasia used to take this image

"Salto del Agrio"

Photographer: Alejandra Heis

Location: Salto del Agrio; Caviahue, Argentina​

The glowing Milky Way isn't the only stunning part of this image; it frames a 148-foot (45 m) waterfall that feeds into a large canyon, created by the lava flows from the Copahue volcano.

"Despite the harsh conditions, I waited for the precise moment when the Milky Way aligned above the waterfall, forming an arch suspended over this ancient terrain," Heis said in the statement. "Working with the tripod close to the ground and repeating exposures, I was finally able to capture the scene I had envisioned for so long."

• Best astrophotography cameras
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• Best beginner astro cameras

Can you name all the animals, objects and mythological figures hiding in the night sky? Find out with our constellations quiz!

Castles were a common sight in the Middle Ages, which lasted from roughly 500 to 1500. Most castles were built to be the fortified residences of local nobility during this politically tumultuous period, but they also functioned as territorial defenses.

Giant stone castles were challenging to take but were not unconquerable. Many fell through sieges, through direct assaults or by bribing the defenders to abandon their posts. But some castles withstood the slings and arrows of their times.

Here are six medieval castles that were never conquered, including one that may have been saved by a dead-cow catapult.

Bohus Fortress (Sweden)

Bohus Fortress, in what is now southwestern Sweden, withstood at least 13 sieges without being taken, according to the Swedish National Property Board. Originally constructed on top of a hill in the 1250s on the orders of the Norwegian king Bohus, it was expanded into a wooden castle in the 14th century. Over the following two centuries, most of the wood was replaced by stone.

At its height, the fortress had multiple towers connected by a complex system of interlocking stone walls. This design meant that if one of the towers was taken, the remaining defenders could continue to fight in another. In 1566, Swedish attackers succeeded in capturing one of the towers. The castle's defenders kept fighting in the other towers and even managed to ignite a gunpowder magazine in the captured tower that then blew up the Swedish invaders.

Bohus was initially built on the old border between Norway and Sweden. But through the peace treaty of Roskilde in 1658, the border was moved and Bohus was ceded to Sweden.

Hochosterwitz Castle (Austria)

Hochosterwitz Castle, in what is now southern Austria, was built on top of a steep hill that rises about 500 feet (150 meters) over the surrounding valley, according to Hochosterwitz Castle's website.

A castle existed on the site at least as early as A.D. 860 and was continually modified and repaired over time, but it does not appear to have been conquered. In the late 16th century, to guard against Turkish invasions, the nobleman who owned the castle built 14 gates, each equipped with different defensive structures.

According to one story, which may be fictional, Hochosterwitz was almost conquered during the 14th century, when the castle was laid siege by an army loyal to Margaret, Countess of Tyrol. The defenders were nearly out of food, so they slaughtered their last cow, filled it with grain and catapulted it at the enemy. Margaret's army concluded that if the defenders could afford to catapult a dead cow with grain in it, they must be well supplied ‪—‬ and they broke off their siege.

Burgdorf Castle (Switzerland)

Burgdorf Castle, near Bern, Switzerland, gave its medieval attackers a lesson in 1383: If you can't conquer it, then buy it.

During a war between the city of Bern and the counts of Neu-Kyburg, the castle, which was controlled by the Kyburgs, was besieged for 45 days by an army sent by Bern. The siege failed, and the Bern army faltered, according to the Historical Dictionary of Switzerland. However, the Kyburgs and the city reached a deal in which the city paid 37,800 guilders, a currency used in the Holy Roman Empire, in exchange for control of the castle.

Burgdorf is far from being the largest medieval castle, but it is sizable: The castle has a residential tower, a keep (fortified tower) and a great hall, all connected by a system of walls, according to the castle's website. It doesn't seem to have been conquered during its 800-year history.

Mont-Saint-Michel (France)

Located on a tidal island in northwestern France, Mont-Saint-Michel is part abbey and part medieval fortress, and it withstood multiple sieges throughout its history. During the Hundred Years' War — a series of conflicts fought between England and France between 1337 and 1453 — Mont-Saint-Michel was besieged by the English multiple times but never fell. The site's location on a tidal island and the strength of its ramparts made the fortress practically impregnable, the fortress Mont-Saint-Michel website says.

In addition to being a powerful fortress, Mont-Saint-Michel was an important abbey. According to legend, the archangel Michael appeared before Bishop Aubert three times in 708 and asked him to build a sanctuary in his honor at this location, the website notes.

Kost Castle (Czech Republic)

Located in the northern Czech Republic, in an area known as the "Bohemian paradise," the Gothic-style Kost Castle was built in the 13th century and expanded over the following two centuries. It contains a series of walls and fortifications, with the "Great White Tower" (the tower's stones have a white color) being the most prominent. It also has a chapel, farm buildings and even a brewery that was built in the 16th century, the Kost Castle website notes.

According to one story, after a failed attempt to take the castle during the 15th century, the leader of the force that attacked it, Jan Žižka, said its walls were as hard as bone. While the story may be fictional, the castle retains the "bone" in its name ("kost" means "bone" in Czech), and it appears to have remained unconquered throughout its history.

Château Pèlerin (Israel)

Château Pèlerin (also known as Atlit Castle) is a Crusader castle located on the northern coast of what is now Israel. Constructed in 1218 by the Knights Templar, its seaside location meant that it could be resupplied by ships, making it more difficult to besiege. The Knights Templar built the fortress as a way to control the coastal route and take back Jerusalem, which fell in a siege in 1187, according to UNESCO.

Within the walls and towers of the fortress were residential areas and a chapel. Château Pèlerin was never conquered, but in 1291, it was evacuated and abandoned after the Kingdom of Jerusalem fell and the Crusaders lost control of most of the Holy Land.

Humans have been fond of decorating and changing their bodies for thousands — if not tens of thousands — of years. Ancient human remains have preserved evidence of various types of body modification. Practices we would recognize today, including tattooing and lip plugging, have been found in 5,000-year-old mummies, while traces of abandoned practices, like foot binding and head shaping, can be seen in skeletons from thousands of years ago.

Just as there are many reasons for modifying one's body nowadays, there were likely many drivers in the past, such as inclusion in a group, expression of one's individuality, and celebration of a life transition.

Here are nine of the most common ways archaeologists have discovered ancient people modified their bodies.

1. Head shaping

Also known as cranial vault modification, the practice of head shaping has been found throughout Europe, Africa, Asia and the Americas, and it may have even been performed by Neanderthals. Head shaping is an ancient practice in which a mother or other caregiver wrapped an infant's head in soft bandages to encourage the skull bones to grow in a particular direction. Archaeologists have recovered numerous examples of shaped skulls, and several experts are working to understand the practice of head shaping and to figure out how far back it goes.

Some of the oldest evidence for head shaping comes from Jilin province in northeast China and from a cave in coastal Liguria, Italy. In both cases, skulls that are longer and narrower than average suggest head shaping occurred at least 12,000 years ago. Some of the many other cultures that have practiced head shaping include Stone Age people in France, Viking women on the Swedish island of Gotland, the Huns in Hungary and Croatia, pre-Hispanic people in Mexico and Argentina, early medieval Europeans and ancient Japanese people.

Today, some infants with plagiocephaly — a flat spot on the back of the head — wear helmets so their skulls will grow in a rounder shape.

2. Foot binding

More than 1,000 years ago in dynastic China, the practice of foot binding was taken up by the elite. This type of body modification involved tightly bandaging the feet of young girls so their bones would shift, creating extremely tiny-looking feet.

China tried to outlaw the practice several times in recent centuries because girls' bones would break, and when healed, the girls faced difficulties walking in their special "lotus shoes." Foot binding persisted in rural areas of China until about 1950, meaning there are likely still some Chinese women alive today whose feet were bound as a prerequisite for a "proper" marriage.

Although the practice of foot binding has disappeared, people today still subject their feet to awkward and uncomfortable shoes like extremely high heels for the sake of "beauty."

3. Body piercings

Because most piercings are made in soft tissue, which does not preserve for very long after a person dies, archaeologists are not sure how far back this body modification practice goes. But some of the oldest known gold earrings, discovered in a cemetery in Varna, Bulgaria, date back to 4600 B.C.

Other evidence of ancient piercing techniques comes from the mummy known as Ötzi the Iceman, who was discovered high in the Italian Alps. Analysis of his body has revealed his earlobes were purposefully stretched, likely as a cultural practice, 5,300 years ago. It is unclear if he wore any plugs in his earholes, though.

And a recent study of 29,000-year-old skeletons found in the Czech Republic revealed that people as young as 10 years old had teeth that were worn down on the cheek side, likely from cheek piercings called labrets. Long-term use of these labrets resulted in flat spots on the people's canines and bicuspids and caused their teeth to crowd together.

Although experts aren't sure exactly when body piercing was invented, since piercings are extremely common today — about 84% of U.S. women have their ears pierced — they may have been common in the past as well.

4. Tattoos

Ötzi the Iceman also gives us the earliest evidence of ancient tattooing, a practice that has continued into the present. Many of Ötzi's 61 tattoos, all of which are simple lines and dots, were placed over areas of the body where he likely had pain from arthritis and injuries, suggesting his tattoos may have been medicinal, similar to acupuncture. Two Egyptian mummies also have linear tattoos, revealing that the practice existed on at least two continents 5,000 years ago.

Tattooing kits dating to 2,700 years ago have been discovered in Polynesia, while highly decorative tattoos have been found on bodies of ancient Pazyryk people preserved in the Siberian permafrost for 2,300 years. In Africa, archaeologists have found Christian tattoos on children in Nubia and adults in Sudan. Rare examples of face tattoos have been found in the Andes as well.

Today, nearly 1 in 3 Americans has a tattoo, and some of us have accidental ones from childhood run-ins with pencils. But maybe think twice about tattooing your eyeball.

5. Neck rings

Neck stretching is much less common than piercing or tattooing. As a body modification practice in some African and Asian cultures, such as the Kayan people of Burma, neck stretching is done by placing an increasing number of stiff rings or coils around a girl's neck. The practice doesn't actually stretch the neck, though, at least not in terms of a change in the vertebrae. Rather, the rings push down the person's collarbones and upper ribs, creating the illusion of an elongated neck, which is considered beautiful. When the rings are worn for several years, a person's neck and upper back muscles can become weak, but targeted exercises can remedy that.

Only one potential archaeological example of neck stretching has been found. In an 11th-century cemetery in what is now Ukraine, archaeologists excavated the skeletons of several women who were buried with an elaborate set of neck rings. Experts are unsure if the rings were from neck stretching, but they interpreted the discovery as an indicator of social status.

6. Dental modifications

Today's dentistry often aims to prevent tooth decay and alleviate the pain of cavities or infected jawbones. The earliest evidence that ancient people fixed their teeth comes from Lucca in northern Italy. About 13,000 years ago, a person's top two incisors were drilled and a tar-like substance was inserted. Artificial teeth used as implants have been found in the mouths of an Egyptian from 5,500 years ago and a Celt from 2,400 years ago. And gold dental work has been discovered in remains from 14th-century Greece and 17th-century France.

But people have also been modifying their teeth for cosmetic purposes for nearly as long. While many of the cosmetic dental treatments people get today are aimed at making their teeth straighter and whiter, that hasn't always been the beauty ideal.

For nearly 5,000 years, people in Taiwan practiced dental ablation, which is the purposeful removal of otherwise healthy teeth, as it was thought to be aesthetically pleasing. And 500 years ago in Gabon in west central Africa, people deliberately removed their top front teeth. In ancient Vietnam, archaeologists discovered that people rubbed their teeth with a paste containing iron to blacken them more than 2,000 years ago. Some experts think tooth blackening was developed as a less-extreme version of dental ablation. The pre-Hispanic Maya often blinged out the teeth of kids with small, round pieces of jade, possibly as a rite of passage into adulthood. And in Scandinavia, the Vikings used an iron file to produce grooves on the top front teeth, perhaps as a kind of group identification or initiation rite.

7. Corseting

Many modern women look at the practice of corseting as a remnant of the Victorian era, when women tight-laced their torsos to produce a fashionable hourglass figure with a waist just 22 inches (56 centimeters) in diameter, on average.

A 2020 study of female skeletons from France and England revealed that some women's bones were permanently modified from extremely tight corseting, resulting in the deformation of ribs and the protruding parts of the vertebrae. Corseting, particularly when started in childhood before a person's bones were fully formed, was a lifelong commitment for many women.

This practice is still around today, but it is usually called waist training. It also involves much more forgiving materials than Victorian boned corsets, such as spandex to hug the midsection and temporarily change its shape.

8. Scarification

Another form of skin modification is scarification, or the purposeful creation of cuts that form permanent designs when scarred over. Scarification, also known as cicatrization, may be as old as the delicate bone tools that could be used to make clean cuts 12,000 years ago, some experts believe. But the practice is better known from modern cultural groups such as the Surma people, who live in South Sudan and Ethiopia, and among some Aboriginal Australians. The reasons behind scarification vary depending on the cultural group, but it has been used over the centuries as a form of group identity, a beautification tool and a rite of passage.

9. Castration

One of the more extreme forms of body modification is castration, or the removal of the testicles. Surgical castration of humans goes back at least 3,000 years, and eunuchs — men whose testicles had been removed — are mentioned in historical records from a number of cultures, including ancient Rome, pharaonic Egypt, the Ottoman Empire and the Qing dynasty. Eunuchs often served as royal guards or government officials in antiquity, but the practice lasted into the 18th century, when some choir boys — castrati — were castrated before their voices changed in puberty to preserve their high singing voices.

But either because the practice was rare or because archaeologists aren't used to looking for skeletal changes associated with castration, very few examples have been found to date. Two skeletons with features consistent with eunuchs were discovered in Roman-era Egypt, but it is unclear if they were eunuchs or intersex.

Two studies of the skeletons of known castrati — opera singers Farinelli (1705-1782) and Pacchierotti (1740-1821) — offer the best evidence for what castration does to a skeleton and how archaeologists might be able to identify eunuchs in the future. Both men's skeletons revealed widespread osteoporosis and longer-than-average limb bones resulting from the hormonal effects of castration. Farinelli also had a thickened skull bone that is commonly seen in postmenopausal women, likely also the result of his prepubertal castration.

While castration to create eunuchs is no longer a regularly practiced body modification, orchiectomies are still done today, most often to treat or prevent cancer.

Human skeleton quiz: What do you know about the bones in your body?

Neanderthals have fascinated scientists since they were first discovered in the 19th century. Their long heads and low brow ridges initially convinced experts that Neanderthals were some kind of evolutionary wrong turn that ended up in European caves.

It took more than a century for researchers to prove that Neanderthals were actually quite intelligent and that they interbred with modern humans (Homo sapiens). The number of discoveries related to Neanderthals' biology and culture has skyrocketed in recent years — and 2025 was a noteworthy year. While we learned that Neanderthals had biological features that were strikingly different from modern humans', this year's discoveries also showed that some aspects of their behavior and culture were similar to ours.

Here are 10 major Neanderthal findings from 2025 — and what they teach us about our own evolution.

1. Neanderthals were the first to make fire.

The hottest — but also somewhat controversial — Neanderthal discovery of the year was that the first humans to make and control fire were Neanderthals living in England more than 400,000 years ago.

In December, researchers announced that they had found reddened clay and heat-shattered flint hand axes at an archaeological site in Suffolk. But the smoking gun was the discovery of tiny flakes of pyrite, a mineral that produces sparks when struck against flint.

Experts have debated for decades whether early human ancestors deliberately made fire or whether they opportunistically used wildfires that sprang up. The combination of flakes of pyrite and charred soil and tools points to Neanderthals' purposeful creation of fire.

The discovery, however, does not tell us whether Neanderthals invented this technology or they learned it from even earlier ancestors, such as Homo erectus. Regardless, the fire evidence shows that Neanderthals were smart enough to figure out how to survive in cold and dark European climates.

2. Neanderthals cannibalized women and children.

Around 45,000 years ago — very close to when Neanderthals disappeared forever — six members of a Neanderthal group were cannibalized, according to a study published in November. Their remains were discovered in the Goyet cave system in Belgium with butchery marks similar to those on animal bones.

This isn't the first time archaeologists have found evidence of cannibalism in Neanderthals. But it is the best evidence experts have to suggest one group — probably Neanderthals but possibly modern humans — deliberately targeted the women and children of another group, perhaps as a way to eliminate the group's reproductive potential.

3. A Neanderthal left the world's oldest fingerprint.

A curious-looking rock found in Spain contains the world's oldest known fingerprint, and it was probably made by a Neanderthal using ocher 43,000 years ago, researchers announced in May.

The team investigating the rock, which is the size of a large potato, thinks that it has face-like features and that the red dot may be a nose. If they're correct, it would mean Neanderthals were creating symbolic art, which could settle a decades-long debate in paleoanthropology.

Not all experts agree that the rock is an early version of Mr. Potato Head, but they do think the fingerprint and its characteristic whorl pattern represent a clear example of Neanderthals' use of red ocher pigment.

4. Neanderthals may have used "crayons."

Scientists in Crimea found three pointy chunks of red and yellow ocher that Neanderthals may have used as early "crayons" 100,000 years ago, according to research published in November.

The hunks of mineral appear to have been repeatedly sharpened, which suggested to the researchers that the ocher was used for culturally meaningful purposes rather than in practical tasks, such as tanning hides.

Although ocher has been found at other Neanderthal sites, not all experts are convinced of the crayon interpretation. Instead, they suggest Neanderthals may have scraped powder from the ocher chunks for another purpose, such as to leave a fingerprint.

5. Neanderthals were low-energy.

In July, researchers discovered that a key Neanderthal gene variant that is still found in some humans today could be detrimental to athletic performance because it limits the body's ability to produce energy during intense exercise.

Researchers found that the Neanderthal version of an enzyme called AMPD1 was different from the one in most modern humans. The Neanderthal enzyme variant allowed adenosine monophosphate (AMP) to build up in their muscles rather than being quickly removed. This AMP buildup is problematic because it makes it harder to produce adenosine triphosphate (ATP), a molecule that the body uses to store energy.

Modern humans who carry the Neanderthal variant of the gene have a lower probability of achieving elite athletic status, the researchers found. But while the Neanderthal variant may have affected their muscle metabolism slightly, it may not have contributed to their extinction.

6. Neanderthals were more susceptible to lead poisoning compared with humans.

In a study published in October, researchers examined 51 teeth from H. sapiens, Neanderthals and other ancestors for evidence of lead exposure. Lead occurs naturally in our environment, but it is known to be toxic at high levels, causing damage to the brain and other organs. Researchers discovered that human ancestors were affected by episodic lead exposure for nearly 2 million years — and that human brains may have evolved some protection against lead poisoning.

Humans living today have a unique version of a gene called NOVA1 that is important for brain development and language skills. The gene also appears to confer greater resistance to lead than other versions of the gene do, such as the one in our Neanderthal cousins.

Therefore, researchers propose, the modern-human version of NOVA1 may have given us a slight advantage over Neanderthals and may have contributed to the demise of the Neanderthals.

7. Neanderthals had a "fat factory" in Germany.

Neanderthals primarily ate meat (and maggots), which put them at risk of developing protein poisoning, a lethal condition that results from eating too much protein and too few fats and carbohydrates.

But in July, researchers announced their discovery of a "fat factory" that Neanderthals may have used to stave off this condition 125,000 years ago. Their survey of nearly 200 animal bones revealed that Neanderthals smashed the bones to get at the marrow inside, which they boiled to extract the fat.

Fat is high in calories, and Neanderthals may have saved it to eat during food shortages. This innovative food-collection method is similar to what some ancient modern-human foraging groups did, suggesting that, in at least one way, Neanderthals were similar to us.

8. Neanderthals lacked a key DNA-synthesizing gene.

In August, researchers investigating the enzyme adenylosuccinate lyase (ADSL) found that the version in Neanderthals was more active than the one in humans. ADSL helps synthesize purine, which is one of the fundamental building blocks of DNA, and an ADSL deficiency is known to result in intellectual disability in modern humans. So researchers modified mice to have a modern-human-like ADSL gene and found that they were better at completing a task to get water.

But even though ADSL deficiency can cause intellectual and behavioral problems in modern-day people, it's not yet clear whether the Neanderthal variant impaired them.

9. Our cousins suffered a population bottleneck.

Even before Neanderthals disappeared forever, their numbers were dwindling because of a population bottleneck, according to research published in February.

Scientists looked at the tiny inner-ear bones of Neanderthals from various time periods and noticed that, around 110,000 years ago, there was an abrupt decline in the diversity of bone shapes. This decline suggests a bottleneck event, when a species undergoes a sudden reduction in variation due to factors such as genocide or climate change.

While the ear bones alone didn't cause the Neanderthals' downfall, the bottleneck may have been the beginning of the end.

10. Neanderthals' blood may have doomed them.

Biologically, Neanderthals had distinct blood variants that separated them from modern humans — and two of those variants we learned about this year may have hastened our ancient cousins' extinction.

In January, researchers discovered that Neanderthals had a rare blood type that may have been fatal to their offspring when they mated with Denisovans or early H. sapiens.

Neanderthals carried a variation of the blood antigen Rh, which gives the positive and negative signs to blood types. Before modern medical interventions, if someone who was Rh-negative was pregnant with a fetus that was Rh-positive, it caused a miscarriage or stillbirth. The researchers found that, if a Neanderthal female mated with a H. sapiens or Denisovan male, there would have been a high risk of anemia, brain damage and infant death. And that might have spelled the end of the line for Neanderthals.

Another study published in October suggested that a fatal red blood cell incompatibility between Neanderthals and humans also contributed to our ancient cousins' extinction. Researchers focused on the PIEZO1 gene that affects oxygen transportation in red blood cells. Neanderthals' version of this gene essentially let their blood cells trap oxygen efficiently, while the modern-human version more efficiently released oxygen to tissues. When maternal oxygen isn't passed on to the fetus, it can restrict the growth of the fetus or lead to miscarriage. So, if a hybrid Neanderthal-human mother mated with a modern-human father or with a hybrid Neanderthal-human father, their offspring would be more likely to die than the offspring of non-hybrids.

Although Neanderthals' extinction likely did not hinge on any one specific gene variant, the new research into red blood cells and maternal-fetal incompatibility is providing key insight into the demise of our archaic cousins around 35,000 years ago.

Neanderthal quiz: How much do you know about our closest relatives?

Groundbreaking medical treatments; mysteries of fundamental biology; the impacts of health policy upheavals. Live Science covered all these topics and more in 2025 — and you can catch up on some of our best Health channel long-reads from the year below. The following list includes interviews, book excerpts and news analyses, as well as entries from our Science Spotlight series, which highlights how science is transforming the world as we know it.

1. Secrets of the world's oldest woman

Maria Branyas Morera, once the world's oldest woman, died in 2024 at age 117. Live Science took a deep look at a study that examined Branyas' biology and uncovered key traits that may have protected her from disease in old age. Could lessons from the study help others lead longer, healthier lives?

2. What makes us human?

Many consider the brain to be a central feature of what makes us human — but how did the remarkable organ come to be? In an interview, science communicator Jim Al-Khalili discussed what he learned from shooting the new BBC show "Horizon: Secrets of the Brain," which tells the story of how the human brain evolved. And in a book excerpt and interview with Live Science, neuroscientist Nikolay Kukushkin described the evolutionary forces he believes were key to the formation of the human brain and consciousness as we know it.

3. Could lab-grown brains gain consciousness?

Miniature models of the human brain can be grown from stem cells in the lab, and they're getting more and more advanced. Some scientists have raised concerns that these "minibrains" could become conscious and feel pain. We investigated experts' concerns and hopes for future regulation of the research.

4. The promise of mRNA medicine

mRNA may be best known for forming the basis of the first COVID-19 vaccines, but it could also be used in revolutionary cancer therapeutics, immune-reprogramming treatments and gene therapies. The promise of these emerging mRNA medicines is staggering, but due to the politicization of COVID-19 shots in the U.S., mRNA research and development — even unrelated to vaccines — now hangs in precarious uncertainty. A Science Spotlight feature described emerging mRNA technologies and their wobbly status under the second Trump administration.

5. Cancer in young people

You may have heard that more young people are being diagnosed with cancer. But which types of cancer are driving this trend? And why are the rates going up in the first place? We looked at what may be driving this pattern, from underlying cancer triggers to better techniques for early detection.

6. Male vs female brains

Is there really a difference between male and female brains? And do we even have the data required to answer that question? A Science Spotlight explored the existing research on sex differences in the brain, finding the results murkier than one might expect. Headlines often proclaim that male and female brains are "wired differently," and that may be true in some subtle ways. But the biological consequences of those differences remain unclear, even to experts in the field.

7. AI is designing viruses

Artificial intelligence can now be used to design brand-new viruses. Scientists hope to use these viruses for good — for example, to treat drug-resistant bacterial infections. But could the technology usher in the next generation of bioweapons? An analysis probed this dual-use problem and what can be done to safeguard our biosecurity.

8. When pandemics are a "certainty," how do we prepare?

In a book excerpt, epidemiologist Dr. Seth Berkley explained how he and other health leaders orchestrated a massive vaccine rollout to poor countries during the COVID-19 pandemic, so that the shots wouldn't exclusively be hoarded by wealthy nations. Live Science also spoke with Berkley about the lessons learned from the pandemic and the ongoing fight for vaccine equity.

9. USAID cuts

The United States Agency for International Development (USAID), once the world's largest foreign aid agency, was hit by massive funding cuts under the second Trump administration. A few of its functions will reportedly continue, under the control of the Department of State. We looked at the predicted and devastating effects that the loss of USAID will likely have on HIV care worldwide. And in an interview with author John Green, who published a book on tuberculosis (TB) this year, we explored what the cuts could mean for TB patients.

10. Microplastics on the brain

A study went viral after suggesting that healthy human brains may contain a similar amount of plastic as the average plastic spoon. But should we really be concerned? Our analysis broke down what we know and what we don't about microplastics in the brain.

11. Dodging early Alzheimer's disease

A man genetically guaranteed to develop early Alzheimer's disease is still disease-free in his 70s. We explored the details of the man's case, digging into his genetic profile and the broader lessons it could teach scientists about dementia.

12. Mental health after weight-loss surgery

Weight-loss surgeries often come with improvements in mental health — but research revealed that this effect is less tied to the weight loss itself and more connected to the relief from stigma that people often experience post-procedure. We examined this finding and what it can tell us about the profound impact of weight stigma on people's health and well-being.

13. Measles makes a comeback

In 2000, the United States hit a public health milestone by eliminating measles. But now, there's been a sustained resurgence of the highly infectious disease, putting the country on the brink of losing that precious elimination status. This story explained how we got here and what's at stake. And in an opinion piece, several experts called out the anti-vaccine movement that drove down measles vaccination rates — a movement that health secretary Robert F. Kennedy Jr. has been spearheading for years.

14. Is America losing the war on cancer?

In a book excerpt, Nafis Hasan argued that the United States has been employing the wrong strategies to fight cancer for decades. While hyperfocusing on finding treatments for individuals with cancer, America has largely ignored population-level strategies that could help drive down cancer rates and cancer deaths across the board, he argued.

15. Threats to fetal tissue research

The U.S. federal government is threatening to restrict research conducted with human fetal tissue. In an opinion piece, cell biologist, geneticist and neuroscientist Lawrence Goldstein dispelled widespread myths and misinformation about this type of research.

16. "The Big One," a disaster to dwarf COVID-19

Epidemiologist Michael Osterholm predicts that the next pandemic could be even worse than COVID-19. In a book excerpt and interview with Live Science, Osterholm described the lessons we should have taken away from the coronavirus pandemic, and how recent changes in U.S. policy may have destroyed our capacity to handle serious outbreaks.

17. Climate change may drive up hyponatremia

As the planet warms, a dangerous condition called hyponatremia may be on the rise. The condition causes a dramatic decline in sodium in the body, which can potentially cause seizures, coma and death. A Live Science exclusive looked at the emerging trend.

18. Baby-making robots?

A viral story suggested that researchers in China were working on a "pregnancy robot" that could gestate a human baby from conception to birth. It turns out that the story was complete fiction — but, in theory, could such a technology be realized? Experts weighed in on the sci-fi-sounding idea and discussed whether, eventually, it could be feasible to build a bona fide pregnancy robot.

Archaeologists have been very busy excavating lost civilizations, but they haven't found everything. There are still prominent ancient cities, including capitals of large kingdoms and empires, that have never been unearthed by scholars.

We know these cities exist because ancient texts describe them, but their location may be lost to time.

In a few cases, looters have found these cities, and have looted large numbers of artifacts from them. But these robbers have not come forward to reveal their location. In this countdown Live Science takes a look at six ancient cities whose whereabouts are unknown.

1. Irisagrig

Not long after the 2003 U.S. invasion of Iraq, thousands of ancient tablets from a city called "Irisagrig" began appearing on the antiquities market. From the tablets, scholars could tell that Irisagrig was in Iraq and flourished around 4,000 years ago.

Those tablets reveal that the rulers of the ancient city lived in palaces that housed many dogs. They also kept lions which were fed cattle. Those that took care of the lions, referred to as "lion shepherds," got rations of beer and bread. The inscriptions also mention a temple dedicated to Enki, a god of mischief and wisdom, and say that festivals were sometimes held within the temple.

Scholars think that looters found and looted Irisagrig around the time the 2003 U.S. invasion took place. Archaeologists have not found the city so far and the looters who did have not come forward and identified where it is.

2. Itjtawy

Egyptian pharaoh Amenemhat I (reign circa 1981 to 1952 B.C.) ordered a new capital city built. This capital was known as "Itjtawy" and the name can be translated as "the seizer of the Two Lands" or "Amenemhat is the seizer of the Two Lands." As the name suggests Amenemhat faced a considerable amount of turmoil. His reign ended with his assassination.

Despite Amenemhat's assassination, Itjtawy would remain the capital of Egypt until around 1640 B.C, when the northern part of Egypt was taken over by a group known as the "Hyksos," and the kingdom fell apart.

While Itjtawy has not been found, archaeologists think it is located somewhere near the site of Lisht, in central Egypt. This is partly because many elite burials, including a pyramid belonging to Amenemhat I, are located at Lisht.

3. Akkad

The city of Akkad (also called Agade) was the capital of the Akkadian Empire, which flourished between 2350 and 2150 B.C. At its peak the empire stretched from the Persian Gulf to Anatolia. Many of its conquests occurred during the reign of "Sargon of Akkad," who lived sometime around 2300 B.C. One of the most important structures in Akkad itself was the "Eulmash," a temple dedicated to Ishtar, a goddess associated with war, beauty and fertility.

Akkad has never been found, but it is thought to have been built somewhere in Iraq. Ancient records indicate that the city was destroyed or abandoned when the Akkadian empire ended around 2150 B.C.

4. Al-Yahudu

Al-Yahudu, a name which means "town" or "city" of Judah, was a place in the Babylonian empire where Jews lived after the kingdom of Judah was conquered by the Babylonian king Nebuchadnezzar II in 587 B.C. He sent part of the population into exile, a practice the Babylonians often engaged in after conquering a region.

About 200 tablets from the settlement are known to exist and they indicate that the exiled people who lived in this settlement kept their faith and used Yahweh, the name of God, in their names. Al-Yahudu's location has not been identified by archaeologists, but like many of these lost cities, was likely located in what is now Iraq. Given that the tablets showed up on the antiquities market, and there is no record of them being found in an archaeological excavation, it appears that at some point looters succeeded in finding its location.

5. Waššukanni

Waššukanni was the capital city of the Mitanni empire, which existed between roughly 1550 B.C. and 1300 B.C. and included parts of northeastern Syria, southern Anatolia and northern Iraq. It faced intense competition from the Hittite empire in the north and the Assyrian empire in the south and its territory was gradually lost to them.

Waššukanni has never been found and some scholars think that it may be located in northeastern Syria. The people who lived in the capital, and indeed throughout much of its empire, were known as the "Hurrians" and they had their own language which is known today from ancient texts.

6. Thinis

Thinis (also known as Tjenu) was an ancient city in southern Egypt that flourished early in the ancient civilization's history. According to the ancient writer Manetho, it was where some of the early kings of Egypt ruled from around 5,000 years ago, when Egypt was being unified. Egypt's capital was moved to Memphis a bit after unification and Thinis became the capital of a nome (a province of Egypt) during the Old Kingdom (circa 2649 to 2150 B.C.) period, Ali Seddik Othman, an inspector with the Egyptian Ministry of Tourism and Antiquities, noted in an article published in the Journal of Abydos.

Thinis has never been identified although it is believed to be near Abydos, which is in southern Egypt. This is partly because many elite members of society, including royalty, were buried near Abydos around 5,000 years ago.

Each week, Live Science highlights an intriguing case report from the medical literature, where we explore unusual symptoms, rarely seen diagnoses and out-of-the-box treatments. Through this "Diagnostic Dilemma" series, we describe how doctors work to ultimately discover the cause of a patient's ailment. In complex cases, this diagnostic process can be quite arduous. That's part of why doctors share case reports: to help other medical professionals who might be facing the same puzzle.

Here are 12 of our most intriguing Diagnostic Dilemmas from the past year. (If descriptions of medical symptoms and procedures make you squeamish, proceed with caution.)

1. Boy spoke foreign language after surgery

A Dutch teenager got knee surgery to treat a soccer injury, and upon waking up from anesthesia, he spoke only English — a language he'd previously spoken only in language classes at school. He kept insisting he was in the U.S., did not recognize his parents, and could not speak or understand spoken Dutch, his native language. Exams turned up no neurological abnormalities, and the doctors didn't initiate any specific treatment to address the language issue. Within 18 hours of surgery, the boy could understand some Dutch but not speak it without struggling. But then suddenly, he could both understand and speak it as normal. The doctors described the event as a strange case of "foreign language syndrome."

2. Woman with no vaginal opening gets pregnant via oral sex

A teenager reported to a hospital with abdominal pain, and examinations soon revealed that she was nine months pregnant and that she was having contractions. When doctors examined the patient's reproductive tract, they found that she lacked a vaginal opening — a rare condition called distal vaginal atresia. Because of this, the medical team had to deliver the baby — a healthy, 6.2-pound (2.8 kilograms) boy — via cesarean section. The teenager had been seen at the same hospital about nine months prior, when an ex stabbed her after finding her fellating a new boyfriend. The wounds she incurred during the stabbing likely allowed sperm to escape her digestive tract and make their way to her reproductive tract, resulting in an unlikely pregnancy, her doctors theorized.

3. Man stabbed by huge fish

A man was brought to a hospital by boat and helicopter after incurring an injury while fishing. He'd caught a white marlin (Kajikia albida) — a large fish with a long, pointy "bill" — and when he leaned over the edge of his boat to release his hook from the fish, it jumped up and struck him. At the hospital, doctors found a fragment of the fish's bill lodged in the man's throat, spinal canal and base of his skull. With an emergency surgery and antibiotics to prevent infections, the man survived the encounter without any long-term symptoms.

4. Acupuncture led to joint injury

A woman with osteoarthritis of the knee began getting acupuncture regularly when her pain medications started causing bad stomach issues. But her knees then became very sore, and she went to a hospital to be examined. X-rays revealed areas of her joints and shinbones where the bone tissue had thickened and spurs had formed. Additionally, hundreds of tiny flecks could be seen around both knee joints. It turned out that the woman's acupuncturists had left golden threads inside her knees on purpose as part of her treatment. In other cases, these threads have caused cysts and tissue damage, which can happen when they migrate through the body.

5. Man experiences rare meat allergy

A man in Michigan went to an ER with swollen eyelids and an itchy rash, and he noted that he'd also been experiencing cramps, nausea, abdominal pain and vomiting over the preceding days. When doctors examined the patient, they uncovered signs of anaphylaxis, a severe allergic reaction, and his condition quickly progressed to shock. The medical team successfully stabilized the patient, but a few days later, his condition worsened again. At that point, the doctors spotted a pattern: The symptoms arose when the man ate red meat. An allergy to meat, a condition called alpha-gal syndrome, can be triggered by the bite of certain tick species. It turned out that the man was an avid deer hunter who likely encountered an adult tick or tick larvae while hunting, his doctors concluded.

6. Woman had XY chromosomes in her blood

A woman had her chromosomes checked following a pregnancy loss to see if there might have been an underlying genetic reason for the miscarriage. The test revealed that, at least in the woman's blood, her chromosomal profile (or karyotype) was 46,XY — the typical karyotype among males. Further tests revealed that across the rest of her tissues, her karyotype was 46,XX, the typical chromosomal profile of a female. The woman had a fraternal twin, so in this case of "chimerism," the doctors concluded that the XY chromosomes likely came from her brother in the womb but somehow assimilated them only into her blood cells. The doctors suspected the "veins and arteries of the two children became intertwined in the umbilical cord" at some point. The woman had no overt symptoms tied to carrying these chromosomes in her blood and later went on to carry a pregnancy that resulted in the birth of a baby boy.

7. Woman injects herself with black widow venom

A woman visited an emergency room with a headache, severe cramps and muscle pain, as well as an elevated pulse, breathing rate and blood pressure. She told doctors she'd attempted to get high by injecting a ground-up black widow spider (Latrodectus) into her veins in a suspension of distilled water. The doctors suspected the injected dose of black-widow venom was likely much higher than one would get from a bite, and its effects may have been exacerbated by the patient's allergic reaction to proteins in the venom. After the patient had been treated for several days in an intensive care unit, her symptoms resolved and she was discharged.

8. Nut allergy was triggered by ejaculate

A woman developed hives, swelling under her skin and trouble breathing after having sex with her partner. While receiving treatment at a hospital, she reported having a known allergy to Brazil nuts. She said that her partner ate them a few hours prior to sex but that he'd taken a bath and washed his hands thoroughly before intercourse. When the doctors conducted a skin-prick allergy test, using samples of the partner's semen, before and after he ate Brazil nuts, they found that the allergy triggers could indeed pass through the semen and set off the woman's allergy.

9. Rash mysteriously migrated

Following a cancer treatment, a man developed a red rash that started out near the anus and then spread rapidly to the trunk and limbs. The rash, which looked like wavy lines all over the patient's body, appeared to migrate, with the lines starting out in one spot and later moving across the skin. A stool test revealed Strongyloides stercoralis, a parasite that can cause an infection called strongyloidiasis in humans. These worms were migrating under the man's skin, and the infection likely arose because the patient's immune system was stunted by glucocorticoids used in his cancer treatment.

10. Rare tooth-in-eye surgery performed

A rare autoimmune disorder injured a man's corneas and extensively impeded his sight. To restore vision in one eye, doctors attempted an osteo-odonto-keratoprosthesis, or "tooth-in-eye surgery." The procedure involves removing one of the patient's teeth and implanting it in their eye socket, where it serves as a platform for a transparent, plastic lens. The lens stands in for the injured cornea and enables light to enter the eye. The man's successful procedure was the first of its kind in Canada.

11. "Muscle-plumping" injections cause calcium spike

A man went to a hospital because he was experiencing weakness and vomiting. There, tests revealed that his kidneys were failing and the calcium in his blood was too high. Physical exams and scans revealed abnormalities in his upper-arm and chest muscles — namely, areas of superdense calcification. It turned out that the man had previously gotten injections of silicone-like, oil-based substances to "plump" up the look of his muscles. In this case, the injections triggered a persistent foreign-body reaction, resulting in extensive scarring and calcification of the muscle that leached calcium into the bloodstream.

12. Scientist catches plague from defanged bacteria

A lab worker came down with an infection that, despite medical treatment, ended up being fatal. His doctors were informed that the patient had worked with a weakened strain of Yersinia pestis, the bacterium that causes the plague. This weakened form of the germ was thought to be noninfectious, but nonetheless, the man contracted it. Further tests revealed that the man had unusually high levels of iron in his blood. One way the plague bacteria had been weakened was that its key gene for absorbing iron had been removed — but the man's blood, which was chock-full of iron, may have enabled the germ to overcome this weakness and establish a deadly infection.

For more intriguing medical cases, check out our Diagnostic Dilemma archives.

This article is for informational purposes only and is not meant to offer medical advice.

Our understanding of how our species evolved has improved dramatically since we first began analyzing ancient DNA. This year, researchers made impressive discoveries across 3 million years of human evolution, most of which relied on DNA, genomic or proteomic analyses.

Here are 10 major findings about human ancestors and our close ancient relatives that scientists announced in 2025.

1. Two new species of human relatives were discovered in Ethiopia.

A handful of teeth found at the Ledi-Geraru site in Ethiopia suggest that diverse species of human relatives unlike any seen before were roaming the area 2.6 million years ago.

In August, researchers announced the discovery of 13 teeth. Ten are estimated to be 2.63 million years old and don't belong to either Australopithecus afarensis or Australopithecus garhi, the two australopithecine species known from the area. Because the teeth don't have any especially unique features and aren't in a skull, the newfound species they may come from does not have an official name. Researchers are calling it the Ledi-Geraru Australopithecus.

In the same study, the researchers found two teeth that are 2.59 million years old and one that is 2.78 million years old. All of them seem to belong to the genus Homo, which would make them some of the earliest remains of our own genus.

The dental discoveries mean that at least three archaic human relatives were living in this region of Ethiopia around 2.5 million years ago.

2. Imported stone tools show our relatives were much smarter than we thought.

Hundreds of stone tools discovered in Kenya revealed that our ancient relatives had a high degree of forward planning 600,000 years earlier than experts previously thought.

In an August study, researchers looked at more than 400 stone tools from the site of Nyayanga dated to 3 million to 2.6 million years ago. The tools were likely not made by our genus. While the tools were fairly basic — flakes chipped off of a larger stone — the stones used to make them came from locations more than 6 miles (9.7 kilometers) away.

The fact that hominins were transporting stones from far away to make tools suggests an excellent ability to plan ahead, long before our genus Homo arose.

3. Earliest evidence of Homo erectus found in Georgia

In July, researchers announced the discovery of a 1.8 million-year-old jawbone from Homo erectus at the site of Orozmani in the Republic of Georgia. In 2022, the paleoanthropologists had found a single tooth that they thought was from H. erectus, and the jawbone discovered this year clinched the identification.

H. erectus was our direct ancestor and evolved around 2 million years ago in Africa. It was also the first human ancestor to leave Africa, and eventually ended up in parts of Europe, Asia and Oceania.

To date, the earliest evidence of H. erectus outside Africa comes from Orozmani and a second site in Georgia called Dmanisi, suggesting human ancestors settled in the Caucasus region shortly after leaving Africa.

4. A mystery human reached Indonesia 1.5 million years ago.

Stone tools discovered on the Indonesian island of Sulawesi this year suggest that either H. erectus or an unknown human relative reached Oceania nearly 1.5 million years ago. This matches up well with previous evidence that H. erectus arrived on the island of Java around 1.6 million years ago.

But because no ancient skeletal remains have been found on Sulawesi yet, researchers are unsure if the toolmaker was indeed H. erectus. Another candidate could be H. floresiensis, the diminutive "hobbit" species, which has been found on the neighboring island of Flores. Some researchers think the hobbits originally came from Sulawesi.

Additional excavation on Sulawesi may eventually clarify which species called the island home.

5. Humans arrived in Australia 60,000 years ago.

Genetic research published in November showed that Homo sapiens reached Australia 60,000 years ago, likely via two different routes through the Western Pacific. This finding appears to settle a long-standing debate about humans' arrival on the continent — a feat that required expert knowledge of watercraft and sailing.

The new DNA evidence supports archaeological evidence, including stone tools and pigments on cave walls, of a "long chronology" in which the first arrivals showed up around 60,000 to 65,000 years ago.

But not everyone is convinced. In a July study, researchers used the fact that some Indigenous Australians have Neanderthal DNA to suggest that Australia wasn't populated until about 50,000 years ago — an idea known as the "short chronology."

More research into the origins of the earliest Australians is forthcoming.

6. Drought may have doomed the "hobbits."

By 50,000 years ago, H. floresiensis seems to have disappeared from Flores. In December, researchers published a study suggesting that drought may have fueled their demise.

While studying the rainfall on Flores, scientists discovered that it declined considerably between about 76,000 and 61,000 years ago and that the population of an elephant relative called Stegodon, which the hobbits hunted, disappeared around 50,000 years ago.

The researchers think decreased rainfall led to the reduction in the Stegodon population, which made life more difficult for the hobbits. And if modern humans also reached Flores — perhaps part of the wave of people who eventually settled Australia — the pressure of competition from another species may have wiped out H. floresiensis.

7. Denisovans got a face.

Our extinct relatives the Denisovans were first discovered in 2010 based on DNA extracted from a tiny finger bone. But until this year, no one knew what a Denisovan skull looked like.

Researchers debated for years what species the thick jawbone, recovered off the coast of Taiwan in 2000, came from, with some suggesting H. erectus and others suggesting H. sapiens. But using paleoproteomic analysis, researchers announced in May that the jawbone was from a male Denisovan.

Ancient proteins also revealed in June that a skull discovered in China in 1933, called the "Dragon Man," is from a Denisovan, finally putting a face to the name. But while Dragon Man has now been slotted into the story of human evolution, it is not yet clear whether the group should be considered a separate species, Homo longi.

And in September, researchers reconstructed a 1 million-year-old squashed skull from China and suggested that it may have been a Denisovan ancestor rather than H. erectus.

These three discoveries are pointing paleoanthropologists to clues about the origins and spread of the mysterious Denisovans — a task that will surely continue in the coming years.

8. Denisovan DNA helped Native Americans survive.

Researchers announced in August that some people with Indigenous American ancestry carry Denisovan genes, likely passed on through Neanderthals who mated with modern humans.

In looking at a protein-coding gene called MUC19, scientists discovered that 1 in 3 Mexicans alive today has a version of the gene similar to Denisovans' and that it likely "hitched a ride" from Neanderthals. Essentially, Neanderthals got the gene from mating with Denisovans and then passed it along when they mated with humans. This is the first time scientists have found a Denisovan gene in humans that came via Neanderthals.

Exactly what the Denisovan variant of the MUC19 gene does is currently unclear, but the researchers think it must have been beneficial to the earliest Americans for it to be preserved in the human genome.

9. Interbreeding was rampant among our archaic relatives.

The story of human evolution has gotten wonderfully messy since the genomic revolution. DNA and protein analyses have revealed new groups like the Denisovans, as well as the mating of Neanderthals, modern humans and Denisovans. But this year brought a few surprise pairings as well.

In August, researchers announced that a handful of 300,000-year-old teeth suggested humans and H. erectus may have interbred in China. The teeth had an unusual combination of ancient features, like thick molar roots, and modern features, like small wisdom teeth, that could mean two different species were sharing their genes.

Researchers announced in March that Neanderthals, modern humans and a mysterious third lineage lived alongside one another in caves in what is now Israel around 130,000 years ago. The Homo groups may have mixed and mingled for 50,000 years, potentially sharing cultural practices in addition to genetic material.

And in November, a DNA study of humans' arrival in Australia suggested that, along the way, these early human pioneers likely interbred with one or more archaic human groups, such as H. longi, Homo luzonensis or H. floresiensis.

Although we can see genetic differences among these groups using 21st-century technology, perhaps our earliest ancestors simply saw Neanderthals, Denisovans and others as fellow humans.

10. Most Europeans had a dark complexion until 3,000 years ago.

In a study published in July, scientists found that the genes for lighter skin, lighter hair and lighter eyes emerged among Europeans only about 14,000 years ago and that, until 3,000 years ago, most Europeans had dark skin, hair and eyes.

The researchers determined this from 348 samples of ancient DNA from archaeological sites spread throughout Western Europe and Asia. The first humans to reach Europe around 50,000 years ago carried genes for dark complexions. Once lighter traits emerged, they appeared only sporadically in the genetic data until fairly recently. By about 1000 B.C., those lighter traits became widespread in Europe.

Whether lighter skin, hair and eyes had any sort of evolutionary advantage for early Europeans is still unclear, though.

Human evolution quiz: What do you know about Homo sapiens?

The final frontier is an unendingly beautiful expanse filled with unimaginable wonders, making it the perfect sandbox for photographers, astronomical observatories and space-based telescopes to capture incredible images that we can hardly fathom. And 2025 was no different.

This year, we covered a range of stunning space images, from an eye-catching alien comet and a planetary parade portrait to the first Vera C. Rubin photos and otherworldly animal lookalikes. Here are 10 of our absolute favorites.

Alien visitor transforms into a "cosmic rainbow"

The biggest space news story this year was undoubtedly the arrival of the third-ever interstellar object 3I/ATLAS, which has dominated headlines and astronomers' attention ever since it was first spotted speeding through the solar system in early July. As a result, there has been no shortage of stunning shots of the alien comet.

Our favorite is this timelapse image captured by the Gemini North telescope on the summit of Hawaii's Mauna Kea volcano. The image was created by combining 16 different photos using multiple colored filters to create a giant cosmic rainbow.

Read more: Interstellar comet 3I/ATLAS transforms into a giant 'cosmic rainbow' in trippy new telescope image

"The Fall of Icarus"

One of the most unbelievable photos of 2025 was this solar spectacle, dubbed The Fall of Icarus, which perfectly captured the moment a skydiver fell directly in front of the sun.

Astrophotographer Andrew McCarthy captured this shot in early November, at a distance of around 8,000 feet (2,440 meters) from the skydiver, YouTuber Gabriel C. Brown. It took six attempts to properly line up Brown with the solar surface before the thrill-seeker leapt from a small propeller-powered craft at an altitude of around 3,500 feet (1,070 m).

"It was a narrow field of view, so it took several attempts to line up the shot," McCarthy told Live Science. "Capturing the sun is something I'm quite familiar with, but this added new challenges."

Read more: Astrophotographer snaps 'absolutely preposterous' photo of skydiver 'falling' past the sun's surface

Vera C. Rubin's stream of stars

In June, the most powerful digital camera on Earth winked on. The Vera C. Rubin Observatory in Chile's Atacama desert revealed its first-ever images in June. These debut photos were chock-full of cosmic treasures, including the spiral galaxy M61 (shown here), which researchers noticed was being trailed by a massive stellar tail around the same size as the Milky Way.

We can look forward to many more spellbinding shots from Rubin in the coming years as it begins its decade-long survey of the night sky.

Read more: First Vera Rubin Observatory image reveals hidden structure as long as the Milky Way trailing behind a nearby galaxy

Perfect planetary parade portrait

In late January and early February, up to six of the solar system's planets were simultaneously visible in the night sky in what astronomers refer to as a "planetary parade." This particular parade was one of the best in recent years, allowing astrophotographers to snap several stunning pics of the event.

Our favorite pick of the bunch is this planetary portrait from French astrophotographer Gwenaël Blanck, which he digitally edited to show each planet alongside the sun in the order of distance from Earth. Blanck snapped each of the individual worlds within 80 minutes of one another.

Read more: Parisian photographer produces phenomenal, perfectly-proportioned 'planetary parade' portrait

Giant "diamond ring" shines in X-ray

All that glitters is not gold, and in this scintillating starscape, released in November, it is high-energy X-rays that sparkle like a giant ring.

This object, dubbed a "diamond ring," is an expanding bubble of gas in a star-forming region of the Cygnus constellation. The glowing bubble is around 20 light-years across and is around 400,000 years old. It was photographed by NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA), which previously scanned the night sky from a telescope onboard a Boeing 747SP aircraft, at an altitude of more than 45,000 feet (13,700 m).

The cosmic ring is not to be confused with Einstein rings, which are rings of light created by gravitational lensing.

Read more: Giant 'diamond ring' sparkles 4,500 light-years away in the Cygnus constellation

A cosmic butterfly spreads its wings

JWST has, yet again, captured some stunning photos in 2025, including the fiery Cigar Galaxy, a tantruming stellar toddler and a "starlit mountaintop" nebula. However, our favorite is this striking portrait of the "Butterfly Star," IRAS 04302+2247.

The insect imposter's shining wings are made from a mini nebula of stellar material leftover from a supernova. This nebula is bisected by a protoplanetary disk that surrounds the baby star like a cosmic cocoon, and just happens to be aligned with Earth so that the two halves of the nebula are seen from side-on. It is located around 525 light-years away, in a star-forming region, known as the Taurus Molecular Cloud.

Read more: James Webb telescope finds a warped 'Butterfly Star' shedding its chrysalis

Arsia Mons rises

Speaking of Mars, NASA's Mars Odyssey orbiter also captured this stunning shot of a giant dead volcano peeking above the clouds on the Red Planet, as eerie green lights dance above the Martian horizon.

The mountain in the image is Arsia Mons, which stands at more than 12 miles (19 kilometers) above the surface of the previously volcanic Tharsis plateau. The extinct volcano is more than twice as tall as Mount Everest, but around 4 miles (6 km) shorter than Mars' tallest peak, Olympus Mons.

The green lights look like auroras. But they are actually just an effect of the image being partially captured using infrared light, which emanates from the planet's wispy atmosphere.

Read more: NASA spots Martian volcano twice the height of Mount Everest bursting through the morning clouds

Seen by the "Eye of Sauron"

There is no escaping the dark lord of Mordor's malevolent gaze, even from halfway across the universe. That's the impression given by this photo, dubbed the "Eye of Sauron," which playfully references J. R. R. Tolkien's fantasy epic "The Lord of the Rings."

The "eye" is actually the magnetic field of a supercharged energy jet being shot into space by a quasar — a supermassive black hole at the center of a distant galaxy. This quasar, dubbed PKS 1424+240, is billions of light-years from Earth and has one of its jets pointed almost directly at our planet, allowing researchers to peer directly through its "jet cone" and map out the magnetic swirls within.

Read more: Giant, cosmic 'Eye of Sauron' snapped staring directly at us in stunning 15-year time-lapse photo

New "heavenly" pillars emerge

This ethereal image shows a set of stellar structures reminiscent of the famous "Pillars of Creation," first seen by the Hubble Space Telescope in 1995. The structure is named Ua 'Ōhi'a Lani, which means the "heavenly rains" in Hawaiin, and this image of it was taken by the Gemini North telescope.

What you are seeing is two distinct regions: the twinkling blue stars of a star cluster, named NGC 6823, overlapping the veil of red gas that comprises a more distant emission nebula, dubbed NGC 6820. The ethereal pillars are made from additional gas and dust that have been sculpted by the foreground stars' intense radiation.

The original pillars of creation were also recently given a glow-up by JWST, which captured the iconic cosmic structures using infrared light.

Read more: 'Heavenly rains': Ethereal structure in the sky rivals 'Pillars of Creation'

Astronaut snaps a giant "jellyfish" over Earth

As incredible as it is to point our cameras out into the universe, space also provides a unique angle of our own planet. And that's exactly the case in our final photo, which shows off a giant, electrifying "jellyfish" hovering above Earth.

The luminous branching structure was snapped by NASA astronaut Nichole Ayers in July, while onboard the ISS. It shows a type of transient luminous event that researchers commonly call sprites. In this case, the red jellyfish-like sprite formed at the summit of a rare upward-shooting "gigantic jet" of lightning, up to 50 miles (80 km) above the U.S.-Mexico border.

If you liked this photo, then be sure to check out Live Science's weekly Earth from space series for more incredible images of our planet from above.

Read more: Astronaut snaps giant red 'jellyfish' sprite over North America during upward-shooting lightning event

Want to see more amazing images of the cosmos?Be sure to check out Live Science's Space Photo of the Week series, or peep our favorite space shots from 2024 or this gallery of stunning James Webb Space Telescope (JWST) images.

This year has seen some of the most destructive extreme weather events on record. Wildfires in Los Angeles were a big part of the equation, but several other events also left devastation in their wake. From winter storms in Louisiana to flash floods in Texas, here's a look at the wreckage from some of nature's most damaging events this year.

Related: Extreme weather caused more than $100 billion in damage by June — smashing US records

Wildfires sweep through Los Angeles

Wildfires swept through the Palisades and Altadena in Los Angeles in January, causing around $58 billion in damage.

Fires extinguished in the Palisades

The Palisades fires left 12 people dead after torching a vibrant coastal community.

Snow storms in New Orleans

Winter storms hit the South, including New Orleans, in January.

Tornadoes carve through Mississippi

In March, tornadoes ripped through Mississippi, leaving brutal scars that were spotted by the Landsat 8 satellite.

Destructive Kentucky floods

Violent rainfall in April hit several states, including Kentucky, leaving large areas underwater.

Tornado strike

Tornadoes also left a trail of devastation across Kentucky in May.

Everglades cracked and dry

In May, parts of Florida's Everglades were left cracked and desolate as the state suffered its worst drought since 2012.

Before and after the river burst

In July, devastating flash floods in Texas left at least 135 people dead. Maxar Technologies satellites captured the area before and after the Guadalupe River burst its banks.

Search and rescue operations

Monroe Canyon fire from space

This false-color image from NASA shows swathes of Monroe Canyon, Utah, burning in July.

Fires burn historic site

In September, lightning caused wildfires to burn through the historic Chinese Camp in California, a Gold Rush town established around 1850.

When Jane Goodall stepped off her boat into what is now Gombe National Park in Tanzania on July 14, 1960, she began a journey that would change science forever.

Armed with her notepad and binoculars, Goodall perched far away from the chimpanzees (Pan troglodytes) she had been sent to observe and worked to gradually build their trust. This patience gave the chimps time to "habituate" — the process whereby wild animals acclimatize to human presence to the point that they start to behave normally around them.

This simple act was Goodall's first revolutionary step, enabling her to follow the chimps and meticulously observe their behaviors and individual quirks. Habituation is now the routine first step for animal behavioral research.

Goodall's legacy in conservation and environmentalism is immeasurable. People across the world praised her accomplishments and grieved her death on Wednesday (Oct. 1) Here are the five biggest ways she changed our understanding of our closest living relatives.

Chimp the Toolmaker

Goodall's first revolutionary discovery was that humans were not unique in making and using tools. In October 1960, she spied David Greybeard — a high-ranking adult male who was the first to relax in her presence — poking a stick into a termite mound to fish out its occupants.

Until this point, scientists assumed that only humans had the brains for such behavior. "It is in making tools that man is unique," Kenneth Oakley, a 20th-century physical anthropologist and palaeontologist, wrote for a conference held at the Natural History Museum in London in 1947. "The shaping of sticks and stones to particular uses was the first recognisably human activity," he said.

The field of chimpanzee, and wider animal, tool use is now a burgeoning research field, with chimpanzees across Africa known to fish for termites, while West African chimps are experts at using stones to crack open hard-shelled nuts. Primatologists now routinely observe chimps using tools to infer how hominins may have solved similar problems, including termite-fishing.

Each to their own

Goodall defied convention by giving each member of the Kasakela chimpanzee community a name, such as Flo, Fifi and Goliath, as opposed to a number. Off the back of this, she noticed that each individual had its own personality, with David Greybeard, for example, being very gentle, while Frodo was a known bully.

Because of Goodall, finding individual differences in how chimpanzees act and think is now unsurprising, but this discovery paved the way for a flurry of research into how personality maps onto behavior. This is important because differences in behavior can have large evolutionary consequences, especially if this impacts the ability to survive and reproduce — the key principle behind evolution by natural selection.

Mother-infant relationships

The birth of a new infant, Flint, in the early 1960s gave Goodall the opportunity to observe mothers caring for their newborns. Every interaction she saw was a new scientific discovery.

For example, Goodall noticed how, as infants mature, mothers began to actively wean their young by denying nursing opportunities and rejecting attempts to hitch a ride on their backs, while simultaneously exposing their infants to more and more social interactions.

Scientists now know that mothers play an essential role in the learning periods for complex behaviours such as tool use. A 2019 study published in the journal PNAS found that chimp mothers in the Republic of Congo could even be actively teaching their infants how to termite-fish by giving them their own stick rods as hand-me-downs.

I'll be there for you

Beyond mother-infant bonds, Goodall also observed that chimpanzees form strong, long-term connections with their family and other members of the group. Research has since found that individual chimpanzees create close bonds with those outside of their own sex and rank, and will share food with their buddies.

Moreover, primatologists now know that chimps have an exceptional social memory that complements these bonds, with 2023 research in the journal PNAS finding that chimps recognize their former group mates almost three decades after they last laid eyes on one another.

As such, Goodall's discovery was key for unlocking the previously unknown social lives of our closest living relatives, and revealed what these relationships can teach us about human social and cultural evolution.

For example, these close relationships, and the corresponding social tolerance this creates, are the foundation for learning in chimps — with chimps acquiring a vast array of behavior from others. In fact, being tolerant toward one's groupmates is argued to be fundamental for primates, including hominins, in evolving to make and use tools.

A taste for blood

Goodall's time in Gombe also revealed that chimpanzees are not the vegetarians they were once believed to be. Instead, they're omnivores who actively hunt for meat. Red colobus monkeys (genus Piliocolobus) are the main prey for the Kasakela community, but it is now known that chimps across Africa hunt a wide range of species.

For example, chimps in Uganda hunt duiker, a type of antelope, while the Fongoli chimps in Senegal craft spears to kill bushbabies.

Goodall also discovered violence between members of different groups, with this discovery paving the way for what is now extensive research into chimpanzee border patrols, group level cooperation and reconciliation behavior.

We now know that oxytocin — the bonding hormone — is involved in post-conflict reconciliation, showing its importance not only in building relationships, but repairing them.

Pirates and the loot they plundered have long fascinated us. Stories like "Treasure Island" and movies like "Pirates of the Caribbean" have helped increase the popularity of these sea raiders. In this countdown, Live Science looks at some of the biggest treasures that pirates have ever plundered.

While valuables were plundered by well known pirates, such as Capt. William Kidd, others were captured by pirates that are much more obscure. Many of the pirates that captured these stashes didn't live long to enjoy them, although a few managed to survive the ensuing manhunts.

Henry Every captures the largest pirate haul in history

In September 1695, a fleet of pirate ships commanded by Henry Every (also known as Henry Avery) attacked a convoy of 25 ships that belonged to the Mughal Empire of South Asia. They succeeded in capturing several ships, including the Ganj-i-Sawai, a ship belonging to the Mughal emperor himself. They stole more than 500,000 pieces of gold and silver, making it the largest prize taken by pirates in history, Srinivas Reddy, a visiting assistant professor of religion studies at Brown University, wrote in a 2020 paper published in the journal Asian Review of World Histories.

Every soon found himself on the run as the British government and the East India Company, a British trading company that conducted extensive business with the Mughals, both put large bounties on his head. While Every was never captured, it's not clear what his fate ultimately was.

William Kidd captures the ship "Quedagh Merchant"

On Jan. 30, 1698, Capt. William Kidd captured a vessel named the "Quedagh Merchant" that was loaded with gold, silver, silks, satins and other valuable goods. Kidd was a privateer, which meant that he had permission from the English crown to attack ships that belonged to England's enemies. However, the Quedagh Merchant didn't belong to England's enemies; it had an English captain and carried goods that belonged to the East India Company and the Mughal Empire, Reddy noted in the paper.

Kidd was branded a pirate by England and was captured in New York City. He was transported to London where he was hanged in 1701. What happened to William Kidd's treasure has long been a source of speculation and led to stories that he hid it somewhere before his capture.

Capture of the ship "Nossa Senhora Do Cabo"

On April 8, 1721, a group of pirate ships captured the Portuguese ship Nossa Senhora Do Cabo (our lady of the Cape) that was carrying cargo being transported for two individuals, the viceroy of Goa (a city and state in India that was controlled by Portugal at the time) and the archbishop of the city. The treasure consisted of ingots of gold and silver, chests full of pearls and a gold cross that weighed about 220 pounds (100 kg) and was studded with rubies, researcher Denis Piat wrote in his book "Pirates & Privateers in Mauritius" (Didier Millet, 2014). While an impressive haul, it didn't end well for Olivier Levasseur (also known as "La Buse," French for "The Buzzard") who was one of the pirate captains. He was captured and hanged on the island of Reunion in 1730.

According to one story, just before he was hanged he tossed a manuscript containing a cryptogram (a coded message) to the assembled crowd and said that it led to the location of some of the treasure — which to this day has never been found. However, some scholars believe that this story is false and the cryptogram that he supposedly wrote was created after his death. Today some modern-day treasure hunters still seek his riches.

Whydah Gally treasure

In January or February of 1717, a group of pirates led by Sam Bellamy captured a slave ship called the Whydah Gally in the Bahamas. The ship had already completed a trip bringing slaves to North America at the time it was captured. Impressed by its size, speed and armaments, the pirates decided to make it their flagship. Their fleet had captured and looted dozens of merchant ships in the Caribbean and much of their plunder was stored on the flagship, the Whydah Pirate Museum notes on their website. Unfortunately for the pirates, the ship sank in a storm on April 26, 1717 and only two people on the ship survived. Bellamy himself was killed when the ship sank.

The survivors claimed that the ship held more than 30,000 British pounds worth of treasure in its hold. That's worth more than 5.4 million pounds ($7.2 million USD) today, according to the Bank of England's inflation calculator. In 1984, a team of explorers succeeded in finding the wreck and in uncovering some of the artifacts, which can now be seen in the Whydah Pirate Museum in Yarmouth, Massachusetts.

Robert Culliford & Dirk Chivers capture the ship "Great Mohammed"

In 1698, the Dutch pirate Dirk Chivers and the English pirate Robert Culliford, along with their crews, teamed up to capture the "Great Mohammed" — a ship carrying pilgrims bound for Mecca, Tim Travers, professor emeritus of history at the University of Calgary, wrote in his book "Pirates: A History" (The History Press, 2009). The captured plunder was worth about 130,000 pounds or more than 19 million pounds ($25.5 million USD) in present-day value, the Bank of England's inflation calculator says.

The pirates took their ill-gotten gains to the island of St. Mary (also known as Saint Marie or Nosy Boraha) near Madagascar. During the trip, the passengers met a terrible fate, with surviving witness accounts claiming that the pirates tortured and raped passengers who were traveling on the Great Mohammed. Both pirates were captured not long afterward; Chivers died in a Bombay prison while Culliford decided to testify against other pirates in exchange for his freedom. It's unclear what became of the treasure.

The honorees for the 2025 Milky Way Photographer of the Year contest are in, and they're stunning.

Created in 2018 by photographer Dan Zafra, the contest showcases shots of the Milky Way taken from around the globe, highlighting gorgeous landscapes on Earth laid out under the twinkling night sky. This year's winners include shots from places as diverse as Namibia, the Himalayas, New Zealand and Yemen. There's even a photo taken from space.

"Starlit Ocean"

Photographer: Xingyang Cai

Location: Big Sur, California

This photograph, titled "Starlit Ocean: A Comet, the setting Venus, the Milky Way, and McWay Falls," was taken during the approach of Comet Tsuchinshan-ATLAS (C/2023 A3) in fall 2024. The comet streaks above the Pacific and a setting Venus at McWay Falls in Big Sur.

"Cosmic Fire"

Photographer: Sergio Montúfar

Location: Acatenango volcano, Guatemala

Photographer Sergio Montúfar captured this stunning image of two types of fire in the sky at Acatenango volcano in Guatemala in June 2024. "Above, the Milky Way stretched diagonally across the sky, a mesmerizing band of stars contrasting with the chaos below," Montúfar wrote in his description of the photograph. "As the volcano erupted, the ash plume rose vertically, forming an acute angle of about 45 degrees with the galaxy's diagonal path, creating a stunning visual contrast between Earth's fury and the cosmos' serenity."

Montúfar used a wide-angle lens (f/2.8), an ISO of 3200, and a 10-second exposure to capture the light of the Milky Way and the light of the volcano at the same time.

"Blossom"

Photographer: Ethan Su

Location: Hehuan Mountain Dark Sky Park, Taiwan

An explosion of alpine rhododendrons provides a stunning foreground to this view of the Milky Way from Mount Hehuan in central Taiwan. A solar flare from the sunspot AR3664 added a slight airglow to the scene, while clouds blocked light pollution from distant urban areas.

"One in a Billion"

Photographer: Don Pettit

Location: Earth orbit

Astronaut Don Pettit captured this image of Earth against the Milky Way from the Cupola of the International Space Station. City lights seem to mirror the jewel-like glow of the galaxy in the background of the image. "There are over eight billion people that call this planet home," Pettit wrote. "There are seven of us that can say the same for [the] Space Station. What a privilege it is to be here."

Related: May's best stargazing week has begun. How to see a lion, an upside-down bear, a mini 'planet parade' — and more.

"Bottle Tree Paradise"

Photographer: Benjamin Barakat

Location: Socotra, Yemen

Four years of scouting Socotra, a Yemeni island in the Indian Ocean, led photographer Benjamin Barakat to this grove of bottle trees (Dendrosicyos socotranus), a species that's unique to the island. These trees' thick trunks allow them to store water to survive Socotra's dry climate. The Milky Way decorates this one-in-a-galaxy site like a bangle of jewels.

"Lake RT5"

Photographer: Tanay Das

Location: Zanskar, Himalayas

Celestial fire and Earthly ice meet in this shot taken at Lake RT5, which sits 18,700 feet (5,700 meters) high in the Himalayas. Photographer Tanay Das camped by this lake to capture this shot of the Milky Way. "I was in awe of the incredible airglow illuminating the Himalayan skies," Das wrote. "The raw image had even more intense colors, but I toned them down to stay true to reality. This was undoubtedly one of the most unforgettable nights I've ever spent in the heart of the Himalayas."

"A Sea of Lupines"

Photographer: Max Inwood

Location: Lake Tekapo, New Zealand

Lupines bloom on New Zealand's South Island in a purple feast for the eyes. The dark skies of New Zealand's Mackenzie Basin — along with a lot of patience — enabled this shot.

"I had to wait until the early hours of the morning for the wind to calm down, but eventually everything became still, and I was able to capture this image," photographer Max Inwood wrote. "Above the flowers, you can see the band of the outer Milky Way, alongside the constellations Orion, Gemini, and the Pleiades. Joining them are the bright planets Jupiter and Mars, with a strong display of green airglow visible along the horizon."

"Spines and Starlight"

Photographer: Burak Esenbey

Location: Karas region, Namibia

The Milky Way slashes across the sky behind cacti and two quiver trees (Aloidendron dichotomum) in Namibia. This was photographer Burak Esenbey's second photography trip to the area, and he found this spot on a location-scouting excursion. "Getting everything in focus was a bit challenging, as I had to get extremely close to the cactus without getting poked," he wrote in his description of the image.

"Boot Arch Perseids"

Photographer: Mike Abramyan

Location: Alabama Hills, California

Photographer Mike Abramyan wanted to photograph the Perseid meteor shower from the Canadian Rockies, but wildfires drove him westward and southward to California's Eastern Sierra, where he captured this stunning image of the Milky Way superimposed with each meteor he photographed — as if they'd all streaked across the sky at the same time.

"Universo de Sal"

Photographer: Alejandra Heis

Location: Jujuy, Argentina

Photographer Alejandra Heis took this photograph while traveling across Argentina's iconic locations. The salt flats of Salinas Grandes in northern Argentina begged for a nighttime photoshoot, despite the challenges of camping on desiccated salt flats at an elevation of nearly 17,000 feet (5,200 m). "I believe I haven't truly experienced a place until I see it at night," Heis wrote. "Nighttime feels more intimate, mysterious, and adventurous — a moment when the senses sharpen and you connect with your surroundings in a deeper way."

Misconceptions abound about Vikings. They are often depicted as bloodthirsty, unwashed warriors with winged helmets. But that's a poor picture based largely on Viking portrayals in the 19th century, when they featured in European art either as romantic heroes or exotic savages. The real Vikings, however, were not just the stuff of legend — and they didn't have wings or horns on their helmets. Here, we debunk seven myths about the Vikings.

Related: Hårby Valkyrie: A 1,200-year-old gold Viking Age woman sporting a sword, shield and ponytail

The Vikings wore helmets with wings and horns.

This idea can be traced to the 19th-century German artist Carl Emil Doepler, who portrayed Germanic gods like Wotan (Odin) wearing winged helmets in his costumes for Richard Wagner's "Ring cycle" of four epic operas, called "Der Ring des Nibelungen" ("The Ring of the Nibelung") in German. Wagner drew on Germanic mythology, but the idea stuck that the related Norse, some of whom were Vikings, also wore helmets with wings. The notion that Viking helmets had horns originated in 19th-century paintings, and it was repeated in Hollywood movies. The myth also may have been inspired by ceremonial helmets with horns found in Denmark in 1942, but those date to about 900 B.C. — over a thousand years before the Vikings.

The Vikings executed enemies with the "blood eagle."

"Blood eagle" execution is described in medieval Scandinavian texts, but it may have just been a gruesome idea, rather than a real practice. According to some Norse sagas, some Viking kings executed their enemies by cutting their ribs from their spine and pulling their lungs out the back to resemble wings; and the sagas give what seemed to be two separate examples of this "blood eagle" punishment. But experts think the sagas may have been exaggerated for dramatic effect, and there is no archaeological evidence to support the notion that this ever happened. Its inclusion in 19th stories about Vikings and in some modern television shows, however, has cemented the idea.

The Vikings were only raiders.

It is undeniable that many Vikings were raiders. But not all of them were, and they were also keen traders and intrepid explorers. Artifacts like Arabic silver coins show that Viking trade networks stretched from Byzantium to the British Isles, and the settlement at L'Anse aux Meadows in Newfoundland, Canada, shows that Vikings reached parts of the Americas from Europe as early as A.D. 1000, almost 500 years before Christopher Columbus did. The Vikings were famous for their trade in furs, walrus ivory and amber, and some modern historians suggest the economic and cultural reasons for the Viking expansion were as important as raiding and taking slaves.

The Vikings were extraordinarily violent.

It is also undeniable that the Vikings were sometimes violent — OK, often. But they lived in a violent age when many societies were equally violent, and there is no evidence that the Vikings were more violent than anybody else at the time. Famous incursions, like the raid on the British island of Lindisfarne in A.D. 793, assured the Vikings of violent notoriety. But brutal wars and massacres were standard throughout early medieval Europe, and the notion that the Vikings were exceptionally more violent than everyone else seems to have been a Victorian invention.

All Vikings were blond.

The idea that all Vikings looked "Nordic" — that is, tall, blond and blue-eyed — may have originated in the racial theories of 19th-century Europe, but the Vikings were a cultural group rather than an ethnic one. Recent DNA studies of Vikings have revealed an admixture of Scandinavians with Southern Europeans, Slavs and even some Saami (or Lapps, a semi-nomadic people from the very north of Scandanvia who traditionally herded reindeer.) Vikings often traveled far afield, to places like Byzantium and the Islamic world, and it is likely that some Vikings had ancestry from those regions. As well, DNA evidence from the graves of Viking warriors indicates some had dark hair and varied features, rather than sharing a racial uniformity.

The Vikings were unhygienic.

The popular image of a Viking is of an unwashed (and smelly) warrior, but the Vikings were actually quite clean for their time. Artifacts from Viking graves show that grooming was a priority, with combs, tweezers and ear spoons for removing wax; while the fragments of Viking bowls indicate soap was often used. Bathing was uncommon at this time, so this Viking custom stood out. The Arab explorer Ahmad ibn Fadlan noted in A.D. 921 that the Vikings in the medieval eastern Slavic region of Rus washed every day — a practice he viewed as odd.

The Vikings were "tamed" by Christianity.

It has sometimes been suggested that the spread of Christianity throughout the Viking world, which supplanted the worship of their Norse gods, eventually made the Vikings less prone to violence — but the idea may just be Christian propaganda. Indeed, the Vikings started out as pagans roughly in the eighth century, and by the 10th century, Harald Bluetooth bragged that he had converted Denmark to Christianity. But the Vikings seem to have been brutal throughout their history, and there is no evidence that Viking violence subsided after their adoption of Christianity; evidence from mass graves indicates that Vikings with Christian beliefs also massacred large numbers of people.

On March 29, a partial solar eclipse swept across parts of the Northern Hemisphere. The edge of the moon's shadow passed across Greenland, most of Europe, northern Asia, northwestern Africa and northeastern North America, including parts of 13 U.S. states.

A partial solar eclipse occurs when the moon passes between Earth and the sun but only partially covers the sun's disk. Unlike in a total solar eclipse, the moon didn't completely block out the sun this time, so observers needed equipment such as eclipse glasses or pinhole cameras to view the sun safely.

Because the eclipse happened at sunrise in North America, seeing the spectacle at its best depended on having a clear view of the eastern horizon and cloudless weather. In European time zones, the eclipse unfolded at midday, making it an easier viewing experience. Sungazers in Greenland and Europe captured these stunning images of the moon taking a "bite" out of the sun.

Nuuk, Greenland

The moon slowly traverses the sun behind a statue of Lutheran missionary Hans Egede in Nuuk, Greenland. Nuuk saw nearly 90% of the sun blacked out during the March 29 eclipse.

Rouans, France

Observers in Rouans, France, were treated to glimpses of the partial eclipse behind clouds around midday.

Brighton, England

The moon carves a bite out of the sun in Brighton, England.

Liverpool, England

Ghostly clouds obscure the sun in this eerie image of the partial eclipse behind the Liver Bird statue in Liverpool, England.

Nuuk, Greenland

A slim crescent of the sun peeks out from behind the moon above a home in Nuuk, Greenland.

Turnov, Czech Republic

Some areas, like the Czech town of Turnov, had their view of the eclipse completely obscured by clouds. Luckily, observers at the Turnov Observatory could watch livestreams of the eclipse on their phones.

Berlin, Germany

Viewers in Berlin, Germany caught the beginnings of the eclipse behind an overcast sky.

The next partial solar eclipse will be visible from parts of Australia and Antarctica on Sept. 21, 2025. Those who wish to experience totality should mark their calendars for Aug. 12, 2026, when a total solar eclipse will be visible in Greenland, Iceland, Spain and Russia, while other parts of Europe, as well as Africa and North America, will experience a partial eclipse that day.

Few technologies have captured the human imagination in quite the same way as robots. The idea of machines that can walk and talk like us has been a staple of science fiction for decades. The reality has been more prosaic — most real-world robots are disembodied arms relegated to dull and repetitive factory work. But recent breakthroughs in both artificial intelligence (AI) and robotic hardware mean that the smart, humanoids of our imaginations are getting ever closer to reality.

Here are 12 of the most important milestones that got us here.

1921 — Invention of the term "robot"

Since antiquity, people had imagined the possibility of artificial humans — from the clay Golems of Jewish folklore to the mechanical servants of the Greek god Hephaestus. History is also littered with examples of complex automata designed to wow audiences with their life-like movements. But the word "robot" was first introduced by the Czech writer Karel Čapek in his 1921 play R.U.R., which stands for Rossumovi Univerzální Roboti (Rossum's Universal Robots). The term is derived from the Czech word "robota," which means forced labor, and the play features artificial workers made of synthetic organic matter that rise up against their human masters — a narrative that would be echoed in many later works.

1942 — Isaac Asimov's Three Laws of Robotics

Robots became a popular science fiction trope, with legendary author Isaac Asimov featuring them prominently in many of his stories. A major theme of his work was how these artificial humans would interact with human society. In his 1942 short story "Runaround" he introduced the Three Laws of Robotics, which were supposed to govern how all robots in his fictional universe operated. The first law prohibited the robots from harming humans, the second mandated robots to obey humans unless it violated the first law, and the third ordered the machines to protect themselves as long as that didn't conflict with the two other laws. While entirely fictional, Asimov's three laws were influential on the development of ethical frameworks for AI and robotics.

1961 — The first industrial robot

It didn't take long for ideas from science fiction to filter through to the real world. In the early 1950s, serial inventor George Devol began work on a robotic arm that could perform repetitive tasks in factories. He teamed up with entrepreneur Joseph Engelberger to form Unimation, the world's first robotics company, and in 1961 their Unimate robot went to work on the assembly line at a General Motors plant in New Jersey. The hydraulically-powered arm had five degrees of freedom (DoF) — a measure of dexterity that means its arm could move or rotate in five different directions. Programming the device required the user to physically move the arm to different positions to teach it the required sequence of actions, which was then recorded in a magnetic storage device known as a drum memory.

1966 — World's first intelligent mobile robot

While significant progress had been made on the mechanical capabilities of robots by the mid-1960s, they were still essentially dumb machines that needed to be programmed by hand. In 1966, researchers at the Stanford Research Institute started work on a wheeled robot with cameras and touch sensors that could reason about its actions, make plans and navigate the real world. It could move between multiple rooms autonomously, avoiding obstacles, opening doors, flicking light switches and pushing boxes around. The robot, which the team named "Shakey," received significant media attention — in 1970 — Life magazine even referred to it as the first electronic person." A key advance behind the robot was its layered software architecture, which enabled it to reason through tasks, something replicated in many subsequent robots.

1969 — The Stanford Arm spawns a new industry

While the Unimate was the first robotic arm to go into production, the Stanford Arm became the blueprint for the emerging industrial robotics industry. Designed in 1969 by Victor Scheinman, who was then a student in the Stanford Artificial Intelligence Lab, the six-DoF arm was electrically powered and controlled by a computer. Over the following years Scheinman built increasingly sophisticated versions of the arm at both Stanford and MIT, before eventually starting a company called Vicarm Inc. in 1974 to commercialize his work. He ended up selling his designs to Unimation in 1977, which released the Programmable Universal Machine for Assembly (PUMA) robot in 1978. The initial customer was General Motors, which used it to assemble automotive subcomponents.

1970 — First robotic rover sent to the Moon

The birth of robotics overlapped with another major technological leap — the advent of the Space Age. Scientists recognized that machines that could be controlled remotely or even operate autonomously could be a powerful tool for exploring the solar system. In 1970, the Soviet Union landed Lunokhod 1, the world's first robotic rover, on the moon. Shaped like a bathtub and with eight independently powered wheels, the rover could be controlled remotely from Earth via antennas and a feed from four cameras. The solar-powered vehicle operated for almost a year, roughly three and half times longer than it was designed to last, and travelled 6.5 miles (10.5 kilometers). It also used extendable probes to carry out more than 500 tests on the mechanical properties of lunar soil.

1990 — Rodney Brooks rewrites AI for robotics

By the 1980s, industrial robots that could carry out repetitive tasks in controlled environments had become commonplace, but efforts to create more flexible and autonomous machines were foundering. Australian roboticist Rodney Brooks had the intuition that this plateau was due to the top-down approach researchers were taking. This involved a focus on imbuing machines with abstract reasoning skills and developing complex systems of mathematical symbols to represent the world around them. Instead, he took inspiration from nature and focused on the feedback loops between sensing and action that enable sophisticated behavior in animals. He demonstrated that by taking this bottom-up approach, outlined in the 1990 paper Elephants Don't Play Chess, it was possible to combine multiple simple behavioral modules to solve challenges beyond the robots that existed at the time.

1996 — Honda unveils first humanoid walking robot

Despite considerable progress in robotics, most machines were a far cry from the mechanical people depicted in sci-fi. That changed in 1996 when Honda unveiled its P2 robot, which was the first humanoid robot capable of walking independently on two legs. The company had started working on the problem of bipedal locomotion in the late 1980s by studying, and trying to replicate, how humans walked. Research on P2 and its successors P3 and P4 eventually culminated in the development of the company's iconic ASIMO humanoid robot, which was unveiled for the first time in 2000 and set the standard for humanoid robotics going forward.

2000 — The da Vinci surgical robot cleared by the FDA

While most commercial robotics companies focused on machines designed to replace brute labor in factories, Intuitive Surgical decided to focus on the delicate process of minimally invasive surgery. They built a four-armed robotic surgical system called da Vinci that could be controlled remotely by a surgeon. The arms were capable of holding surgical instruments like scalpels, graspers and scissors and enabled the surgeon to carry out ultra-precise movements. The device was cleared for use by the U.S. Food and Drug Administration in 2000 and has been used in more than 14 million procedures.

2010 — Google unveils self driving car project

There had been scattered experiments in autonomous vehicles over the years, but the first company to devote serious resources to the idea was Google. The firm began developing self-driving cars in 2009 and drove more than 140,000 miles on public roads before announcing the project in October 2010. Earlier experiments were carried out in a modified Toyota Prius with a safety driver behind the wheel. But in 2015 the company carried out the first fully autonomous ride on a public road in a custom-built vehicle with steering wheel or pedals. After rebranding as Waymo, the company started its first public trials of a driverless taxi service in Phoenix, Arizona in 2017.

2012 — The DARPA robotics challenge is launched

One of the major catalysts for recent breakthroughs in smart, humanoid robots was the DARPA Robotics Challenge. Launched by the Defense Advanced Research Projects Agency in 2012, the competition challenged teams to develop semi-autonomous robots that could carry out complex tasks in simulated disaster zones. The bots were tasked with walking across rubble, climbing ladders, closing leaky valves and even driving a utility vehicle. The finals were held in 2015. While some teams competed with their own robots, six were provided with humanoid Atlas robots built by Boston Dynamics. The company continued to develop the robot after the competition was over, showing off increasingly advanced capabilities over the years such as running outdoors, jumping and tackling parkour courses.

2020 — The first bipedal robot goes on sale

The startup Agility Robotics became the first company to release a commercial bipedal robot after selling two units of its Digit model to Ford. While not strictly a humanoid, thanks to its "backward" legs that work more like a bird's than a person's, the robot is roughly the size and shape of a small human and designed to help out in warehouses and other industrial settings. The release marked the beginning of a boom in commercial humanoid robotics, with companies like Tesla, Figure and 1X unveiling their own offerings shortly afterwards. And costs are falling rapidly — earlier this year Chinese company Unitree released its G1 humanoid robot, which costs just $16,000.

Caves are natural shelters. Throughout our history, humans have made extensive use of them as spaces to create art, inter the dead and butcher animals for food and clothing. In this countdown, Live Science takes a look at seven incredible caves that people used over the ages, leaving behind evidence of their crafts, dead and leftovers. Some of the caves were used by our now-extinct relatives, including the Neanderthals, Denisovans and Homo erectus.

Lascaux cave

Lascaux cave in southwestern France contains about 680 painted frescoes and 1,500 engravings that were created around 21,000 years ago, according to the French Ministry of Culture. Much of the artwork shows animals, including depictions of horses, bison, deer, bears and aurochs (Bos primigenius) — a species of now-extinct bovine. The artwork also features geometric elements, including dots, lines and pentagonal shapes. One of the paintings may show a human figure with a bird-like head, possibly someone wearing a mask. At the time the art was created, people were living as hunters and gatherers, and it's possible that rituals of some form took place in the cave.

Chauvet cave

Chauvet cave in southeastern France has drawings and engravings that date to around 32,000 years ago, according to the Metropolitan Museum of Art in New York City. The cave's interior includes images of horses, bears, lions, rhinoceroses, deer, panthers, bison, owls and mammoths. The remains of human handprints have also been found inside Chauvet. Many of the drawings were created using either red or black ochres. There is one enigmatic image that shows the lower half of a woman's body alongside what appears to be a bison.

Zhoukoudian caves

Located near Beijing, China, the Zhoukoudian caves contain remains of our ancestor H. erectus — sometimes called "Peking man." Many of the fossils were lost during World War II, but excavations have been carried out at the site in recent times with a team carrying out a re-excavation of the cave in 2012. Scientists have found the remains of stone tools that were used for scraping and softening animal hides. These hides were probably used as clothing. It's still debated when Peking man used the caves, but it may have been at different times between roughly 200,000 and 800,000 years ago. Homo sapiens also made use of the caves around 18,000 to 11,000 B.C., UNESCO reports. Remains of their burials have been found within the caves.

Cave of Swimmers

The "Cave of Swimmers" is located in southwestern Egypt in an area that is now arid and has relatively little plant and animal life. The cave gets its name from rock art that depicts people who appear to be swimming. Other art in the cave shows people who appear to be running, walking or engaged in other activities. There are also images of human handprints and an engraved antelope's hoofprint, according to the British Museum. The artwork's age is a matter of debate, but it may have been created between 6,000 and 9,000 years ago — a time when the environment in the region was much wetter.

Denisova cave

Denisova cave is located in Siberia, Russia. A hermit named Denis lived there in the 1700s, which is how it became known as the "cave of Denis" in Russian. The cave's archaeological remains indicate that at least three hominins — H. sapiens, Neanderthals and Denisovans — likely occupied the site at different points in time. Stone tools found in deep layers indicate the cave's earliest residents lived there around 300,000 years ago, the University of Oxford reported.

Other finds include hominin bones and teeth, as well as the bone of a 13-year-old girl who was a Denisovan-Neanderthal hybrid. Archaeologists have also unearthed pendants made of animal teeth that date back between roughly 43,000 and 49,000 years ago that were likely made by H. sapiens. The remains of stone tools that were likely used for butchering animals have also been discovered.

Atapuerca caves

The caves of the Sierra de Atapuerca in Spain were used by people from nearly 1 million years ago to modern times, according to UNESCO. Neanderthals and Homo sapiens both used the caves, and Homo antecessor, Homo heidelbergensis and H. erectus may also have used them. The remains of tools and animal bones indicate that people were butchering bison in the caves about 400,000 years ago. Rock art, both painted and engraved, has been discovered in the caves and includes depictions of animals, people and geometric motifs.

Cave of Altamira

The cave of Altamira in Spain was used by humans roughly 36,000 to 13,000 years ago, according to the Bradshaw Foundation. The cave is about 885 feet (270 meters) long and contains a vast amount of rock art. (A replica of the rock art is seen above). Perhaps the most remarkable example is a ceiling with colorful paintings depicting 25 bison that are up to 5.6 feet (1.7 m) in length, alongside two horses and a deer. To create this ceiling artwork, prehistoric artists engraved and outlined the figures and then colored them in with paint made from ochre, the foundation notes.

There are countless megalithic sites around the world, but while Stonehenge may be the most famous, know this: it is not the oldest or biggest. The site of Göbekli Tepe, in Turkey, dates back about 11,000 years, making it more than double Stonehenge's age. Additionally, Stonehenge is not the biggest megalithic monument, with the site of Avebury in southwest England having a stone circle with a larger diameter. Read on to take a look at seven megalithic sites around the world that rival Stonehenge.

Related: Ancient people lived at German 'Stonehenge,' site of brutal human sacrifices

Göbekli Tepe

At more than 11,000 years old, Göbekli Tepe consists of a series of megalithic enclosures that were built close together. The site is located in southeastern Turkey, a place that was once part of Upper Mesopotamia, and was built at a time when people in the area lived as hunter-gatherers.

T-shaped stone pillars that were up to 18 feet (5.5 meters) tall were used to build the enclosures. The pillars contain carvings of animals such as foxes, boars, gazelles, snakes and vultures. The carvings also include depictions of abstract symbols and figures that look like humans.

Exactly why Göbekli Tepe was built is a source of debate. It's possible that it was used for religious ceremonies or gatherings. The site was built long before writing was invented, so no historical records exist.

Avebury

The site of Avebury originally had a stone circle with a diameter of about 1,378 feet (420 meters) making it the longest known stone circle in the world, a team of scientists wrote in a 2019 paper published in the journal Antiquity. Inside this stone circle there are the remains of two smaller stone circles, each of which was about 328 feet (100 m) across.

Avebury was created around 2500 B.C., at around the time Stonehenge was in use. The site appears to have been part of a larger megalithic landscape. At the time people in Britain practiced a mix of agriculture, hunting and gathering. Researchers have noted that two avenues of paired standing stones leave from Avebury and go toward other megalithic sites in the region.

Ring of Brodgar

The Ring of Brodgar is located on the largest of the Orkney Islands in Scotland. Dating back to around 2500 B.C., it has a stone circle that originally consisted of 60 stones, of which 36 survive Historic Environment Scotland notes. The stones range from 6.9 feet to 15.4 feet (2.1 to 4.7 m) tall, creating a circle with a diameter of 341 feet (104 m). In addition to the stone circle, there are 13 prehistoric burial mounds located close to the site, indicating that ceremonies commemorating the dead may have taken place at the site.

Ale's stones

Ales Stenar (a name which means "Ale's Stones" in Swedish) consists of 59 boulders, weighing up to 4,000 pounds (1,800 kilograms), that were arranged in the shape of a ship. Located by the side of a cliff near the Swedish fishing village of Kåseberga, the date of the structure is a source of debate, with estimates ranging from 1,000 to 2,500 years ago. Its purpose is also uncertain. One idea is that the site may have been used as a solar calendar.

Rujm el-Hiri

Rujm el-Hiri is located in Golan Heights (a region claimed both by Israel and Syria) and dates back around 6,000 years. It consists of a series of stone circles with a tumulus, or mound, in the center. Other tumuli are located nearby. The site is known by a few different names including the "Wheel of Giants" and the "Levantine Stonehenge."

It's unclear what exactly the site was used for. The tumuli suggest it was used for burial, perhaps for important people who lived in the area during prehistoric times. It has also been proposed as a site for astronomical observation, but recent research suggests that this is unlikely.

Spanish Stonehenge

Dating back around 7,000 years, the "Dolmen of Guadalperal," also known as the "Spanish Stonehenge," is located in what is now a human-made lake in western Spain. It consists of about 150 standing stones that are arranged around a central oval area. Some of the standing stones are more than 6 feet (1.8 m) tall. A large stone appears to mark the entrance to the site, and is engraved with an image of a human and what could be a river or snake. The archaeological site was covered with water after a series of dams were built in the 1960s.

Carnac stones

The Carnac stones, located in Brittany in northwestern France, date back around 6,000 years. They consist of about 3,000 stones, the largest of which is about 21 feet (6.5 m) tall, according to the Centre de Monuments Nationaux. They are arranged into circles and linear rows, while a few, like the stone that is 21 feet tall, are located away from the others and appear to stand alone.

The purposes and exact dates of the stones are uncertain, but it appears that some of them mark the locations of graves. What kind of religious or ritual practices occurred at the site is also uncertain, but people appear to have gathered at the stones for thousands of years.

LAS VEGAS — Not only have tens of thousands of people descended on Las Vegas for CES 2025, but numerous robots of all shapes and sizes are at the international tech event too. From therapeutic machines to robot dogs and everything in between, CES 2025 proved that robotics has come on in leaps and bounds in recent months.

Thanks to artificial intelligence (AI) and engineering advancements, all kinds of cute, amusing, helpful, unusual — and terrifying — machines are now emerging. These are the highlights that Live Science picked out at this year's show.

1. Pixar-looking robotic lamp

If you crossed the iconic Pixar lamp with a stylish, wooden side table, you might get something that looks a bit like Mi-Mo. Developed by Jizai, Mi-Mo is the first iteration of the company's general-purpose customizable AI robot, with standard and pro models available. We spotted the little robot waving using one of its wooden legs and rotating its lamp face — but it can do so much more, thanks to several layers of AI software that enable the machine to adapt to its surroundings. Later this year, Jizai will release a toolkit to enable developers to build apps and software for the bot, before the company begins releasing customizable hardware. But it will set you back around $30,000 for the more advanced version.

2. A droid that can help at home

We are beginning to see more and more robots that are designed to perform tasks at home, and R2D3 is among the most advanced we've encountered to date. This droid includes AI that enables the robot to learn over time; different hardware that can be swapped, added and removed; as well as sensors that help the robot adapt to its surroundings.

3. Pool-cleaning robot that returns home to charge

Although there are plenty of intriguing pool-cleaning robots out there, the Wybot S2 Pro model is the first that's configured to return to its dock and charge wirelessly. The dock can be fitted onto the side of your pool, with the Wybot attaching itself to the unit when required. When its battery level dips below 20%, the roving robot automatically searches for its charging dock and begins to recharge — filling its battery tank up in three hours and lasting 3.5 hours between charges.

4. A spherical drone that can roll (and also fly)

Unlike most small commercial drones, which generally have four propellers in a particular arrangement above the body, HAGAMOSphere is a device with eight propellers mounted on a cubic frame and placed in a spherical chassis. The drone not only flies horizontally and vertically in any direction, but it can also roll and rotate on the ground. Its creators hope to see it deployed in various disaster-recovery scenarios in the future.

5. A humanlike android that wants to get to know you

Meet Aria — a humanlike, AI-powered android that's designed specifically to get to know you and become a companion. RealRobotix engineers used several layers of proprietary AI, combined with hardware designed to make the android as human-like as possible, to create a robot they think can bridge the gap between humanoid robots and humans. Although not quite an artificial general intelligence (AGI) agent, Aria is designed to be context-aware and can learn more about you over time — making it ideal either for commercial usage in customer-facing roles or as a romantic companion, representatives told Live Science.

6. The robot vacuum with so much under the hood

You could be forgiven for thinking this is just another robot vacuum cleaner at first glance, but popping out from the center are robot appendages — and even a display that disguises itself as the robot's face — that enable it to do so much more. The SwitchBot K20+ Pro can perform multiple tasks in the home thanks to its robotic arm and finger grips — from cleaning up trash to serving as a humidifier.

7. The robot turtle that wants to clean up the ocean

BeatBot, the creator of pool-cleaning robots, unveiled its robotic turtle concept at CES 2025. The bot can be released into vast bodies of water to help purify them and to conduct research. The solar-powered robotic turtle is a relatively small unit — around the size of a robot vacuum cleaner — and is designed to help resolve ecological challenges.

8. Samsung's Star Wars-style home droid

It's hard to believe that Ballie — the concept AI-powered robot that looks a bit like a Star Wars droid — is already five years old. But the bright yellow, rolling smart home companion is finally getting released commercially this year, Samsung representatives announced during a press conference at CES. Responding to "Hey, Ballie," the robot comes with plenty of sensors, a projector and AI features that are designed to help you complete daily tasks, such as giving you directions. It also has a 2K camera on its rear and a 4K camera on its front.

9. Unitree's backflipping quadruped

The maker of one of the fastest humanoid robots in the world came to CES 2025 in Las Vegas to showcase its latest models, including a rather eerie quadruped robot — commonly known as a "robot dog" — that impressed crowds with its acrobatics and agility. In one trick, the robot stood up on its hind legs like a meerkat and scuttled around the show floor surveying the gathered attendees.

10. A tiny robot dog that can teach you coding skills

This robotic canine looks more like a dog than other eerie quadrupeds we've seen, but it's so small you can hold it in the palm of your hand. The tiny robot caught our eye dancing in response to voice commands, but it is also fully programmable, company Davy Robot says, and could be a way to teach youngsters how to code.

11. A fantastical android with an animated face

The Mirokaï, a 4.3 foot-tall (1.3 meters) robot that moves using a rollable ball rather than legs, is among the most eye-catching robots at CES — not only for its bright colors but also its interactive, cartoonish face. The unusual design incorporates a digital rather than physical face, and its creator Enchanted says it can navigate a space autonomously and become familiar with new people and environments.

12. A robot created with your smartphone

The engineers at Tangible Future who created LOOI say this robot is a "visitor from a distant galaxy" — and its cheery expression, using just two eyes to communicate different moods, evokes a similar charm to Disney's WALL-E. You can connect your smartphone to this device to be its main user interface, and the built-in ChatGPT engine lets you interact with it and play games.

13. A furry creature that hooks onto your bag

This adorable (or slightly unsettling) miniature robot can cling onto your bag and interact with people around you. Mirumi resembles a sloth and uses a built-in measurement unit and distance sensor to blink its googly eyes and rotate its head, depending on who is near.

14. A robotic coffee machine

This robotic all-in-one coffee machine did impress us initially — especially its ability to examine any photo and translate it into intricate coffee art. But the whole process, from choosing your drink to taking your first sip, takes a long time, and the machine malfunctioned during the demo when it ran out of water. So a good old coffee machine — or even just relying on a barista — is probably a safer bet if you don't mind a more classic design on your cappuccino.

15. ADAM — the robotic mixologist

The robotic bartender ADAM uses AI to mix the perfect drink, scientists at Richtech Robotics say. It can be configured to make coffee or boba tea (or bubble tea) too. This is thanks to its software that includes an extensive drinks library. It also interacts with customers, company representatives say, and provides drink recommendations.

16. An autonomous wheel that transforms objects into robots

Although technically not a robot, this moving box caught our eye as it rolled through the halls at CES 2025. This was all made possible thanks to wheel.me — the world's first autonomous wheel, which is capable of turning any object into a robot. All you would need to do is choose an object, mount the wheels, configure the robot with software and set it loose.

17. Arobot that can beat you at chess (and other games)

This chess-playing robot is considerably smaller than Deep Blue — the huge AI supercomputer that famously beat Garry Kasparov in 1996. But this AI-powered game-playing robot can master chess, Go and checkers (depending on the model). Its maker, SenseRobot, hopes to mass produce its mobile game-playing robots for kids who want to learn or as a training partner for professionals. The robot's Apex Duel mode puts users up against an opponent with an ELO3200 skill level in chess — higher than all world champions, with no human going above 3,000 ELO points.

LAS VEGAS — With CES 2025 in full swing, hundreds of innovators, engineers and manufacturers have descended on Las Vegas to showcase cutting-edge and exciting technologies. These range from devices that are set for commercial release to those that are more experimental in nature.

There are plenty of new technologies on show, with a significant number leaning on artificial intelligence (AI) — although there are plenty other technologies worth highlighting. Live Science is on the ground and we've selected a handful of innovations that have caught our eye so far.

1. World's 1st holographic windshield display

Drivers of future electric vehicles (EVs) could be using a holographic display that spans the breadth of their windshield. Developed alongside the optics company Zeiss, Hyundai Mobis' new windshield display is a first-of-its-kind innovation that projects key information, such as navigation and safety alerts, in a panoramic and immersive way. Mass production of this technology will begin in 2027, representatives said.

2. A haptic pendant that beats along to music

Titan is a company that builds advanced haptic motors (or small devices that generate vibrations in things that you hold) for smartphones and gaming devices— but its latest innovation is a relaxation device designed to be worn around the neck. "TITAN Ono" is a pendant that taps into "high definition" haptics to send vibrations through your chest based on a handful of pre-configured modes that may help entertain or calm you. You might, for example, want to feel the sensation of a cat purring, or a heart beating. The device can also be connected to Bluetooth headphones and deliver haptic sensations that accurately mimic the way your chest cavity resonates when you listen to booming live music.

3. An AI-powered reader for children's books

Winner of a CES 2025 Innovation Award, Woongjin ThinkBig's Booxtory is an AI-powered reading device that uses technology to outsource the effort of parents reading to their kidss. You can place a book down in front of the device and the onboard camera uses optical character recognition (OCR) technology to take in the words — with an in-house generative AI system reading out the words through a connected speaker. Its plethora of features includes switching between different preset voices, or even training the AI with a sample of your own voice.

4. The motor-free haptics technology that uses oil

Scientists from Japan have developed a new type of haptics technology called "SoftMRF" that can replicate specific textured feelings, like pushing your hands into the sand. Rather than using motors, the engineers add a small amount of oil into an actuator — a device that converts energy into mechanical motion — before running a current through it. The viscosity of the recreated oil changes with the magnetic field, which allows them to precisely control the level of resistance and the specific sensation you feel when you, for example, push a trigger on a joystick.

5. AI-powered TV that can isolate different sound sources

Toshiba has showcased a handful of ways that AI can transform the viewing experience at home. The highlight is an in-built software for your TV that detects different types of audio coming through — such as commentary and crowd noise during a sports game — and allows you to isolate one particular track at the push of a button. In another example, demonstrators isolated the voice of a reporter during a news segment — and then pushed a button to dampen the reporter's voice and broadcast just the sounds of traffic. The technology is still in development with no fixed release date.

6. The paperlike digital art display with a year-long battery life

InkPoster is the world's first low-power and high-resolution display that lets you upload and display full-color pieces of artwork on your walls using e-paper technology. The battery life lasts for up to a year on a single charge. The largest model has a 31.5-inch (80 centimeter) 2,560 x 1,440-pixel rectangular display — all featured in an aluminum frame with a matte finish. Each one is also Wi-Fi compatible and only needs a power supply when new images are being uploaded.

7. The satellite internet smartphone add-on

HMD OffGrid is ideal for anybody who's regularly on the move. This device can be linked with your smartphone to enable you to tap into satellite internet networks so you can carry on receiving and sending messages to friends and family while also beaming up regular location updates — especially in areas that have no internet or cellular signal whatsoever.

8. The headset that puts you in a "sound bubble"

The Skyted 320 is a headset unlike any other — not only does the microphone isolate your voice, but the device itself creates an invisible sound bubble around you that makes sure nobody 2 feet (0.6 meters) away from you can hear your voice. The technology relies on lowering the sound threshold at which your voice can be picked up by the microphones, representatives said. The minimum voice level activation is 40 decibels, whereas most devices need you to speak at a volume of at least 90 dB — the microphones will also isolate your voice and dampen any background noise for the person you're speaking with.

9. A fridge that can cook

Figo is a refrigerator that fits on your countertops that can cook and store food until it is ready to be prepared with sous-vide cooking — a method of cooking that involves sealing food in a bag and submerging it in water heated to the precise temperatures required. This device lets people effortlessly schedule meals that they prepped a couple of days previously. The idea is to promote better food consumption habits, according to EatFigo representatives.

10. The first 'rollable' laptop

Lenovo has debuted a 2-in-1 laptop with a new rollable display, making it the first machine of its kind ever launched.

Related: Best laptops for photo editing 2025: Notebooks for designers and photographers

The ThinkBook Plus Gen 6 Rollable offers a second display above the standard 14-inch (35.5 cm) screen, extending the screen's real estate to 16.7 inches (42.4 cm). You can activate the additional screen space either by tapping a dedicated key or by making hand gestures to the camera. This form factor sets it apart from 360-degree 2-in-1 laptop-tablet hybrids or even foldable devices.

11. The first transparent and wireless TV

First debuting at CES 2024, LG's wireless and transparent 4K OLED TV, dubbed "Signature OLED T" is now commercially available — if you have at least $60,000 to spend. The "true wireless" technology that LG has given this device is amisnomer, given there are two standard power cables with the set-up that powers the display itself and a companion box. You can plug in any cabling, like HDMI, into the companion box, and set this anywhere in your home up to 30 feet (9 meters) away — ideally with a clear line of sight. The box then transmits the data to the panel itself via Wi-Fi.

12. Drunk driving detector

There have been several previous attempts to design an in-vehicle drunk driver detection system without the need for a breathalyzer, including an algorithm with 75% accuracy. But scientists at research company VinAI claim to have beaten that figure with "DrunkSense" — a passive detection system that scores 85%.

13. An app that can boost your memory, thanks to AI

A memory-boosting app that's new to the U.S. is taking advantage of AI's ability to learn and improve with new training data. By asking you various questions, the app builds a profile of your memory before testing it and attempting to improve it over time by tailoring specific exercises to you to stretch it.

14. A wearable 'memory capsule' that records your voice

Note-taking and transcription are time-consuming, but plenty of software-based AI services can cut down the workload. Plaud AI takes this one step further with hardware-based note-taking devices that use large language models (LLMs). At CES 2025, company representatives showed off the NotePin, a device that can be worn on your wrist like a watch or around your neck like a pendant. With it, wearers can begin recording and transcribing at the push of a button.

15. Extended reality aviators that let you see your computer screen

Lenovo engineers have created a pair of aviator sunglasses fitted with optical technology that beams the screen from any PC, phone, laptop or tablet compatible with DisplayPort technology directly onto the lenses. It works by plugging it into a laptop, sitting back and using the sunglasses as a screen. Note, you'll still need to control your device with your keyboard and mouse (or touchpad).

16. A tiny, punchy ultrasonic loudspeaker for your phone, watch or glasses

Phones, smart glasses and open wireless stereo (OWS) earbuds could soon deliver much punchier sound with a new 0.04-inch-thin (1 millimeter) chip that creates sound by generating waves above the human hearing range. The tiny "Sycamore" processor is three times thinner than dynamic drivers, xMEMS representatives told Live Science, and can be placed in various devices to deliver a much more consistent sound across all frequencies — including plenty more bass. This is thanks to components that tap into the piezoelectric effect to generate sound, like the same company's ultrasonic chip designed for earbuds and headphones.

17. A desk chair with inbuilt cooling and heating

RAZER debuted a desk chair concept that incorporates a fan system that blows either warm or cool air at the push of a button. The integrated fan system sucks in air from the unit at the bottom and pipes it through the chair's skeleton, blowing the air out through grills where your neck would normally rest. The temperature of the air delivered can reach as high as 86 degrees Fahrenheit (30 degrees Celsius) while it reduces the perceived temperature by 35 to 41 F (19 to 22 C) versus room temperature.

18. A battery-free wireless keyboard

HP has created a wireless keyboard and mouse that don't rely on batteries — instead, the devices contain a supercapacitor, which has a much higher power density and faster charging time than batteries. Just three minutes of charging with a USB-C port can give the keyboard two months of life before running out of charge and one month for the mouse, Kevin Wentzel, HP's product experience strategist, told Live Science.

Robots were once consigned mainly to routine tasks in manufacturing and logistics, but now they are slowly spreading their mechanical limbs and stretching into many other areas of life and science.

While many of these recent robots are useful, some are just plain weird. Some use advanced algorithms to render them unsettlingly human-like, while others have bizarre designs aimed at specific tasks.

Read on to meet seven of the weirdest robots you can find in the world right now.

Injectable nanobots

They might sound like something from a cyberpunk movie, but injectable nanobots are already a reality. Researchers from the University of Edinburgh's School of Engineering have developed tiny magnetic robots formed of blood-clotting drugs that are designed to melt at a specific temperature, thanks to a special coating. These bots, which are around one-12th the size of a red blood cell, can be guided through blood vessels, via external magnets and medical imaging, to the part of the body where the drugs need to be administered. Once at that ideal location, the magnets cluster the nanobots together, which causes them to heat up and melt, releasing their payload of drugs.

Atlas by Boston Dynamics

Boston Dynamics' Atlas bipedal robot platform continues to evolve. Atlas previously demonstrated rudimentary parkour skills and surprising dexterity. Now ithas been taught to "wake up" from a prone slumbering position in a manner that's rather unsettling. Starting from a face-down position, the robot bends its legs backwards past its hips and then uses rotatable hip joints to apply force and raise itself from the ground.

It may seem like an eerily unnatural movement, but it's a good demonstration of Atlas' articulation and flexible movements and could make it better able to work in different fields.

Ameca

Dubbed "the world's most advanced robot," the second-generation version of Ameca now comes with the ability to display particularly realistic facial expressions based on its responses to queries.

A malleable material covering Ameca's face, combined with generative artificial intelligence (AI), enables the bot to respond to all manner of queries and then perform hand movements and facial expressions to complement its answers. Those facial movements are uncannily human-like, especially when contrasted with the rest of the robot, which uses a skeletal frame with visible hydraulics and looks extremely artificial. While Ameca has yet to be deployed in a commercial setting, its creators at Engineering Arts envision the humanoid robot's future as helping in social care or serving as a receptionist alongside actual humans.

Torso by Clone Robotics

A robot powered by a system of battery-operated water pumps and valves doesn't sound hugely strange, but Torso is somewhat unnerving. That's because it uses this system to move a range of artificial bones and muscles, replicating the human torso from the pelvis upwards — all covered in a ghostly white skin. Despite this human-like frame, the Torso's movements are relatively jerky, though it's being trained to move in a more natural manner.

Clone Robotics, the company behind the robot, eventually hopes this technology will be used in humanoid robots that work on assembly lines, carry out household chores or even aid in telehealth delivery.

Related: Meet 'Chameleon' — an AI model that can protect you from facial recognition thanks to a sophisticated digital mask

mCLARI

Spiders have long inspired robots in science fiction, but the mCLARI actually exists. At just 0.8 inches (2 centimeters) long, the mCLARI is a tiny "spider-bot" that uses four leg modules that can move in two different dimensions, meaning the robot can effectively change shape to get through tight spaces and bypass obstacles.

While the robot doesn't feature any advanced AI processing and needs to be controlled remotely, its adaptive form could see it pave the way for robots that could crawl among the rubble of a collapsed building or the destruction left by a natural disaster to hunt for survivors in areas that are difficult to reach.

Desdemona

Desdemona is a humanoid robot developed by Hanson Robotics — the company behind Sophia the Robot, which became the world's first "robot citizen (of Saudi Arabia, to be precise) in 2017."

Desdemona uses a large-language model (LLM) for its brain and has synthetic skin that can replicate realistic facial expressions. But unlike similar humanoid robots, Desdemona isn't simply a tech demonstration, it's also a robot music star that's being set up to be a cultural figure with its own style and "personality core" — essentially a database filled with traits and memories that can inform Desdemona's future interactions. Desdemona is less about technology and more about a vision of how robots could become social and cultural figures like their human counterparts.

MenteeBot

While it may look like a rather retro robot, with articulated hands that move with all the grace of a bus, there's a lot more to the MenteeBot than meets the eye. Specifically, it's been designed to learn as it goes, tapping into AI models to respond to different situations and tasks, such as helping push a trolley cart for someone in a wheelchair. MenteeBot features a "Sim2Real" system that cuts down the time it takes to move from a simulated task to a real-world one. This, when backed up by reinforcement learning techniques, a sensor suite and a mix of actuators, could yield a robot in 2025 that can help with tasks ranging from warehouse automation to aiding in domestic environments.

Casio Moflin

Robot pets are nothing new, but the Casio Moflin is one of the first that's aimed at cuddling and developing a bond with its users. Resembling a lump of fur crossed with a hamster, Moflin carries tech that enables it to develop a simulated personality and recognize its owner's voice and how its user handles it.

Unlike other robot pets, such as Sony's Aibo dog, the Moflin hasn't been designed to chase balls or be an active pet — rather, it's built around offering a comforting companion to humans and building a rapport with them. Moflin doesn't need to be fed but will simulate feeling sad or anxious if it doesn't get regular interactions, and those interactions in turn will help develop Moflin's personality.

This year will be an exciting time for space missions.

2025 kicks off with two moon landing attempts in January, followed by SpaceX's daring demonstration to transfer propellants between two Starship vehicles in low Earth orbit — a critical step in testing the company's ability to use the spacecraft to reach the moon and Mars. Later in 2025, Europe will launch an uncrewed robotic laboratory, and NASA's Juno spacecraft may reach the end of its extended mission and burn up in Jupiter's dense atmosphere.

Here are the coolest space missions to look forward to in 2025.

Blue Ghost 1 and Intuitive Machines' moon landings

In mid-January, Texas-based Firefly Aerospace will launch the "Ghost Riders in the Sky" mission, which aims to ferry a moon lander with 10 NASA payloads. The moon lander will head to Mons Latreille, a volcanic feature on the near side of the moon that was formed by volcanic eruptions over 3 billion years ago.

The lander, called Blue Ghost 1, is expected to operate during the daylight hours of one lunar day, or roughly 14 Earth days, during which it will gather data about the moon's regolith, or rocky surface, and how that rock interacts with the solar wind (the stream of charged particles that flows out of the sun's outer atmosphere) and Earth's magnetic field.

Toward the end of its mission, Blue Ghost 1 will take images of the moon's sunset and collect data about what changes occur on the lunar surface at dusk.

Meanwhile, Texas-based Intuitive Machines hopes to land its IM-2 spacecraft at the moon's south pole in February. The spacecraft aims to measure the regolith's volatiles, or delicate chemical compounds, using a drill and mass spectrometer. The spacecraft will also carry a small satellite, Lunar Trailblazer, which is designed to map water deposits on the moon to help NASA identify future landing sites for its Artemis missions IM-2 will fly a more direct route than Blue Ghost 1 and aims to land on the moon just a week after launch.

SpaceX's attempt at daring in-orbit propellant transfer

SpaceX is gearing up for a groundbreaking test to transfer propellant from one Starship to another while docked in low Earth orbit. The demonstration, scheduled for March 2025, will involve launching two windowless Starship vehicles about three to four weeks apart, with the second serving as a refueling tanker for the first.

This test is a crucial step in demonstrating that the spacecraft can be used to reach the moon and, eventually, Mars. Current NASA plans to reach the moon and Mars rely on the Human Landing System variant of Starship. In theory, astronauts who board the Human Landing System as a part of the Artemis 3 mission will reach the moon no sooner than mid-2027.

First NASA-ISRO Earth science mission

Also in March 2025, NASA and the Indian Space Research Organisation (ISRO) are teaming up to launch the first of their spacecraft on the Earth-observing NASA-ISRO Synthetic Aperture Radar (NISAR) mission, which will scan much of Earth's land and ice nearly every week. Using a pair of radar instruments that can see through clouds in both day and night, the spacecraft will measure the motion of Earth's surface down to fractions of an inch. Such precise measurements will help scientists track land movements that may be precursors to volcanic eruptions and earthquakes, as well as monitor changes in forests and agricultural lands.

The U.S. and India are also partnering on a high-profile effort to send the first Indian astronaut — Indian Air Force test pilot Shubhanshu Shukla — to the International Space Station no sooner than April 2025 on the private Axiom Mission 4.

Liftoff of delayed "Blue" and "Gold" Mars satellites

NASA's two Mars-bound satellites, which were designed at the University of California, Berkeley, will study how and when the Red Planet lost its atmosphere. They are now slated to launch no earlier than spring 2025, following a delay of the mission's original October 2024 launch.

The satellites — named "Blue" and "Gold" as a nod to UC Berkeley's school colors — will orbit Mars at different altitudes to gather simultaneous data on the planet's plasma and magnetic fields. With this information, scientists hope to learn how atoms are stripped from the Red Planet's atmosphere.

The mission, called Escape and Plasma Acceleration and Dynamics Explorers (ESCAPADE), was paused in September due to concerns that the delivery vehicle, Blue Origin's New Glenn rocket, wouldn't be ready. The alignment of Earth and Mars creates an ideal launch window every 26 months, so even small schedule changes can cause months-long delays. The spring 2025 launch will include a necessary gravity assist past Venus, which will lengthen the flight time by 1.5 years.

China's mission to snag samples from a near-Earth asteroid

China is preparing for an ambitious mission to scoop up pieces of a near-Earth asteroid, return them to Earth, and then explore a comet in deep space. The Tianwen-2 spacecraft, which is scheduled to launch in May 2025, will rendezvous with 469219 Kamo'oalewa, a quasi-moon of our planet that was discovered in 2016. Ground-based observations suggest that, unlike most near-Earth asteroids, 469219 Kamo'oalewa may have been blasted from the moon's surface by a major impact between 10 million and 1 million years ago, relatively recently in the solar system's history.

Tianwen-2 will carry out remote sensing observations to assess potential landing sites before attempting to collect samples from the space rock. Then, the spacecraft will deliver the extraterrestrial bounty to Earth and use our planet's gravity to fling itself into a seven-year trajectory that will take it to the main-belt comet 311P/PANSTARRS in the mid-2030s.

Juno's potential death swirl into Jupiter

NASA's $1.1 billion Juno spacecraft has been studying Jupiter and its moons since 2016. The mission, which had been extended, will finally end in September 2025 as the spacecraft swirls into the gas giant, unless it survives Jupiter's intense radiation.

According to the mission plan, Juno's orbit will degrade naturally, allowing Jupiter's gravity to pull the probe into the planet's dense clouds. The final hurl, which will last about 5.5 days, will ensure the spacecraft and any Earthly bacteria that may have hitched a ride don't accidentally contaminate Jupiter's ice-crusted moon Europa, which scientists consider one of the best places in our solar system to search for alien life.

Europe's launch of reusable uncrewed robotic laboratory

The European Space Agency's (ESA) Space Rider, an uncrewed robotic laboratory about the size of two minivans, is expected to launch in the third quarter of 2025. The space plane will stay in low Earth orbit for two months, during which the robotic laboratory will automatically conduct technology demonstrations and experiments in microgravity.

At the end of its mission, Space Rider will deorbit and land on a runway at Europe's spaceport in French Guiana and get refurbished for at least five more flights. The space plane is ESA's bid to provide commercial customers with affordable end-to-end launch services, with a broader strategy to help Europe maintain independent, routine access to and from low Earth orbit.

With the growth of artificial intelligence (AI) and advancements in robotics and quantum computers, technology has never been so significant in shaping our lives as it was in 2024. From rogue AI to swarms of drones sparking UFO reports, here are our top 10 tech stories of the year.

Poisoned AI went rogue

As AI becomes ubiquitous, researchers have grown louder in their calls to regulate the software to prevent it from harming society. Of all the studies warning of machine learning's remarkable potential to lie and cheat, perhaps the most troubling one came at the start of the year, when researchers behind one study deliberately poisoned their AI so it would evade all attempts to become more honest.

No matter what training technique or model size they used, a large language model that had been poisoned continued to misbehave. And one technique even taught the AI to recognize the trigger for its malicious actions and better hide its unsafe behavior from human scrutiny.

ChatGPT's GPT-4 passed the Turing test

The Turing test, first suggested by computer scientist Alan Turing in 1950 as the "imitation game," is a thought experiment used to decide when a machine's intelligent behavior is indistinguishable from a human's. And this year, one paper showed that GPT-4 handily passed it: It fooled human participants into thinking that it was a real person 54% of the time.

Still, that doesn't mean machines have reached or surpassed human intelligence. The Turing test isn't really meant to measure intelligence but rather to highlight how poorly human assumptions about it map onto machine behavior. Nonetheless, AI's ability to fool us could become a challenge for future interactions with the technology and a cause for paranoia about the true nature of online interactions in the years to come.

AI won the Nobel Prize, twice

AI research leaped into the highest ranks of scientific honors this year, nabbing the Nobel Prize in both physics and chemistry. The physics prize, awarded to Geoffrey Hinton and John Hopfield for their pioneering work in developing artificial neural networks and machine learning algorithms, surprised many scientists, with some even arguing that AI is unrelated to the fields it won prizes for.

Hinton shared some of this astonishment, saying he was "flabbergasted" upon receiving the news. He compared advancements in machine learning to the industrial revolution, "but instead of exceeding people in physical strength," he said, "it's going to exceed people in intellectual ability."

Meanwhile, the chemistry prize went to David Baker, Demis Hassabis and John Jumper, for their work in using computer and AI technology to revolutionize our understanding of how proteins fold.

Pokémon Go has been secretly farming user data to power future robotic navigation

The controversy surrounding AI's farming of user data took an unexpected turn this year when Niantic, the company behind the popular augmented reality game Pokémon Go, revealed that it had been scraping data from users to help future robots navigate the physical world.

The data, taken from scans made while users were out hunting Pokémon, has already been used to train 50 million local neural networks (collections of machine learning algorithms structured like the human brain) to operate in more than a million locations worldwide, the company said. Experts warned that not all of the applications will be benign.

Google's AI search feature made a bizarre debut

One big issue with AI is its tendency to make things up when it lacks training data. So when Google's Gemini-powered AI overview feature appeared this year, social media reacted with amusement and dismay to a flood of crazed suggestions made by the chatbot — including advice to eat rocks, add glue to pizza, and jump from the Golden Gate Bridge to cure depression.

Google has said it has taken action to remove the erroneous suggestions and is working to improve the quality of the overview's responses. But the overall accuracy of the tool for specific queries and its broader impacts on the news ecosystem it uses for training remain unclear.

A quantum computer smashed an error record by a factor of 100

While still being in their infancy, quantum computers made a series of significant advances in 2024. For instance, Quantinuum's 56-qubit H2-1 computer demonstrated a remarkable reduction in its error rate — a necessary area of improvement for quantum computers to replace classical ones someday. This year, H2-1's error rate improved to 35% of the time, according to a new study. This represents a dramatic 100-fold improvement in the 2019 error rate demonstrated by Google's Sycamore quantum computer.

China's maglev train broke the sound barrier, and it could be faster than a passenger jet soon

China's T-Flight train, a prototype high-speed train that uses magnets to float above its track, reached a blistering 387 mph (623 km/h) this year, breaking a previous record by 12 mph (19 km/h). But what generated buzz was the next plan for the train: a theoretical top speed of 621 mph (1,000 km/h), which the China Aerospace Science and Industry Corp. intends to reach in testing soon.

Drones sparked UFO fever in New Jersey

For weeks, people across New Jersey and other states have been spotting clusters of drone-like objects flying across night skies, leading state officials to push the FBI for answers.

The exact explanation for the uptick in sightings remains unclear, but it seems that increased drone flights in the area, along with a healthy dash of social media hysteria, are behind the phenomena. This isn't the first time that drones have caused UFO panics, and with their growing accessibility around the world, it's unlikely to be the last.

The fastest humanoid robot was announced

Humanoid robots have been growing in sophistication over the past decade, and this year was no different. The Chinese company Robot Era unveiled its STAR1 bipedal robot, which broke records with a top speed of over 8 mph (3.6 meters per second) over a variety of terrains. Part of this accomplishment is owed to some bespoke sneakers attached to the robot's feet, giving it an extra boost of speed.

AI created proteins "not found in nature"

In July, scientists announced that they had used a large language model to create a new type of protein that shares only 58% of its sequence with those found in nature. The model, dubbed ESM3, could prove useful in finding new drugs and in designing chemicals that can decompose plastics, the researchers said.

Arguably the most complex organ in the body, the brain is an elegant mess of cells, chemicals and electrical impulses that orchestrates our thoughts, behaviors and unconscious bodily functions.

This year, Live Science covered a slew of fascinating studies about the brain, each of which revealed new insights about how the organ ticks while also raising new questions.

Related: Master regulator of inflammation found — and it's in the brain stem

The male hormone cycle and the brain

Although not often discussed, the male hormone cycle is quite striking. Steroid hormones in the male body — including testosterone, cortisol and estradiol — decrease about 70% throughout the day and then reset overnight. This year, a brain-scan study revealed that the brain loses and regains volume in time with this daily cycle. At this point, though, it's unclear whether the hormones themselves drive the brain changes or how this cycle affects male brain function.

Your brain on cinema

Many people throw on a movie when they want to "turn off their brain" for a bit. But a recent study found that, actually, 24 different brain networks light up as you watch different types of films. By tying brain activity patterns to what was happening in a given scene, the scientists behind the study were able to construct the most accurate functional brain map to date.

Transformation of babies' brains after birth

A groundbreaking study in fetuses and newborns highlights how the activity of certain parts of the brain suddenly shift after birth. There is a huge uptick in activity in the subcortical network, which acts like a relay hub for information, and the sensorimotor network, which is responsible for processing external stimuli and coordinating movements. The researchers now want to study the same brain networks in preterm babies, to see if there's a notable difference from full-term babies.

The drive to eat

A simple circuit made of just three types of neurons may underlie our drive to eat, a study found. The brain cells work together to detect hunger-signaling hormones and ultimately set off cells that control the muscles for chewing. By messing with this circuit in lab mice, the researchers prompted the rodents to eat 12 times more food than usual and make chewing movements even when they had no food.

Pregnancy's "permanent etchings" on the brain

Throughout pregnancy, about 80% of the brain's gray matter loses volume. Some of this lost volume reappears postpartum, but much of the missing matter stays lost. A similar loss of gray-matter volume is seen during puberty, a time when the brain is "pruning" away excess connections to boost its efficiency. It may be that this change in pregnancy reflects a similar fine-tuning of brain circuitry, scientists say.

Three copies of each memory

A mouse study suggests that the brain may store at least three copies of every memory it encodes. These copies differ in when they're created, how long they last and how modifiable they are over time. Understanding when and how these different copies form could help scientists address conditions that affect memory encoding and retrieval, such as PTSD and dementia.

Conscious lab-grown brains?

Could brain organoids — miniature models of the brain grown in the lab — ever gain consciousness? Live Science posed the question to neuroscientist Kenneth Kosik, who assured us that it's not likely to happen anytime soon. However, there is still ongoing debate about what qualifies as "consciousness," he noted. And there are big questions about what could happen if human minibrains were transplanted into animals or hooked up to technologies to create so-called cyborgs.

Related: Optical illusion reveals key brain rule that governs consciousness

'Shrooms that "dissolve" sense of self

Psilocybin, the active ingredient in magic mushrooms, may cause the brain network responsible for maintaining a person's sense of self to fall out of sync. Called the default mode network, this brain circuit is most active when people are self-reflecting and not engaged in any particular task. On high-dose psilocybin, the network's activity temporarily changed, with some of the effects lasting a few weeks.

Origin of psychosis

A brain-scan study could help confirm a theory about why people experience psychosis, or sudden breaks from reality. Using artificial intelligence (AI) to analyze the scans, scientists found overlapping "signatures" in the brains of people with psychosis. These signatures were either tied to a genetic condition or were from an unknown cause. The findings back a theory that, in psychosis, brain networks in charge of directing a person's attention malfunction, which leads to hallucinations and delusions.

"Universal" brain pattern in primates

Multiple primate species, including humans, share a common brain-wave pattern in the cerebral cortex, the outer surface of the brain. This universal pattern is marked by high-frequency brain waves in the upper layers of the cortex and slower waves in its deeper layers. Scientists think the interplay of fast and slow waves dictates which information remains in conscious thought at any given moment.

Flow state

Scientists revealed the key parts of the brain that switch on when someone is in a flow state — or "in the zone." The study involved scanning the brains of musicians with varying degrees of experience. It pitted two competing theories of "flow" against each other, and one theory came out on top.

Reading in a "blink"

A study found that the human brain can discern the basic structures of written language in the time it takes to blink. That suggests the brain can process written phrases about as quickly as it does visual scenes of the world around us. The study's subjects seemed to process phrases that included subjects, verbs and objects faster than they did lists of nouns. They were also quick to process when the meaning of a phrase didn't quite make sense. The findings suggest the brain isn't only detecting that words are present but also starting to parse meaning right away.

Big brains from gut bugs

A mouse study suggests that humans' remarkably big brains may have evolved partly thanks to the unique microbes in our guts. The study researchers transplanted microbes from the guts of humans and nonhuman primates into mice. The microbes from humans and big-brained primates converted food into energy for the brain more efficiently compared with the microbes from small-brained monkeys. The findings suggest that the big-brain microbes convert food into energy for the brain more efficiently, thus helping fuel the organ's growth.

Stunning new brain map

Researchers from Harvard and Google unveiled a striking map of a small sliver of the human brain. It contains roughly 57,000 neurons, 9 inches (23 centimeters) of blood vessels and 150 million synapses (the connection points between neurons). The map highlighted unique and unexpected features of the brain, including mysterious "whorls," or knots, in the outgoing wires of some neurons.

3D-printed brain tissue that actually works

In a first, scientists 3D printed functional human brain tissue. The printer itself used stem cells instead of ink, and the team then used a concoction of chemicals to spur those cells to transform into brain cells. The resulting cells could communicate and link up in networks, similar to cells in an actual brain.

Ever wonder why some people build muscle more easily than others or why freckles come out in the sun? Send us your questions about how the human body works to community@livescience.com with the subject line "Health Desk Q," and you may see your question answered on the website!

An astronomical observatory, gold tongues found in mummies, a sword inscribed with the name of pharaoh Ramesses II and a 4,500 year-old attempt to treat cancer are just some of the interesting ancient Egyptian discoveries made in 2024. Here are 10 of the biggest discoveries from ancient Egypt this year.

Related: Possible bust of Cleopatra VII found at ancient Egyptian temple

First astronomical observatory

Archaeologists uncovered what they believe is the first astronomical observatory ever identified in ancient Egypt. Dating back to the sixth century B.C., the L-shaped structure spans 9,150 square feet (850 square meters) and has a gateway to the east from where an observer could track the sun and stars. Archaeologists also found a large stone sundial and a carving of an observer watching the sun.

Governor's daughter

The tomb of Idi, a governor's daughter who lived during the reign of Senwosret I (circa 1961 to 1917 B.C.), was found in Asyut. She was buried in two coffins — one within the other. The coffins are covered with intricate texts that were intended to help the deceased find their way in the underworld. It's very rare to find intact coffins that date to this time period, archaeologists noted. While her tomb was robbed in ancient times, parts of her skeleton remain.

Gold tongues

A number of gold tongues, dating back around 2,000 years, were found at the site of Oxyrhynchus. In January 2024 archaeologists announced the discovery of two gold tongues; then in December 2024 they noted that 13 more had been found at the site. Combine this with gold tongues found at the site in previous years and the total number found so far is at 29. The ancient Egyptians believed that gold tongues could help the deceased speak in the afterlife.

Ramesses II sword

A bronze sword inscribed with the name of pharaoh Ramesses II (ruled circa 1279 to 1213 B.C.) was discovered in the remains of a military barracks in the northwest Nile Delta. The sword was likely given to a high-ranking officer as a royal reward. The fact that it was found in a small room near an area where an enemy could infiltrate suggests that this sword was intended for fighting and wasn't just for show.

4,300-year-old wall paintings show everyday life

A 4,300-year-old tomb decorated with wall paintings that depict scenes of everyday life was found at Dahshur. These scenes show donkeys threshing grain by trampling over it, ships sailing the Nile river and goods being sold at a market. The tomb belonged to an official named Seneb-Neb-Af and his wife Idet, who was a priestess of the goddess Hathor.

Copper pollution in Great Pyramid harbor

Scientists found traces of heavy copper pollution in the harbor near the Great Pyramid, which was used to bring in materials and laborers. The harbor is dried up now, but the team analyzed its sediments. They determined that contamination peaked around 4,500 years ago, the time that the Giza Pyramids were built, with copper levels reaching five to six times the natural background level.

30 ancient Egyptian tombs in Aswan

Archaeologists discovered more than 30 tombs nestled in a hillside in Aswan. The tombs were in use between the sixth century B.C. and the second or third century A.D. Many of the burials consisted of families buried together. About 30% to 40% of the mummies in the tombs were children and newborns. Scientists also found that anemia and infectious disease were the most common causes of death.

Evidence of 2,200-year-old hallucinogenic ritual found in vase depicting dwarf god

Scientists found a blood-colored hallucinogenic concoction in a 2,200 year-old vase that depicts the dwarf god Bes. This is evidence that the Egyptians may have engaged in a hallucinogenic ritual that helped reenact a mythical story. In that story, the dwarf god Bes tricks the sky goddess Hathor. Hathor was in a bloodthirsty mood, but Bes gave Hathor an alcoholic beverage, spiked with a plant-based drug disguised as blood, that put her into a deep sleep of forgetfulness.

Ancient Egyptians tried to treat cancer 4,500 years ago

Scientists found evidence that the ancient Egyptians tried to remove a tumor from the skull of a man who lived around 4,500 years ago. The skull contained evidence of a large primary tumor as well as smaller tumors. Evidence suggests that someone tried to remove the cancer using metal surgical instruments. While the attempt was unsuccessful, it shows that the ancient Egyptians were trying to develop treatments for cancer at around the time the Giza pyramids were being built.

2,100-year-old temple discovered hidden in cliff face

A 2,100-year-old temple was found hidden in a cliff face at the site of Athribis. Archaeologists excavating the temple there found a relief showing King Ptolemy VIII (reign circa 170 to 116 B.C.) offering sacrifices to the lion-headed goddess Repit and her son Kolanthes. They also found astronomical symbols such as two decans, or stars that enable people to tell the time at night. These decans were depicted with humanoid bodies and animal heads.

Black holes are terrifying, monstrous objects with immense gravity that causes them to consume everything that crosses their event horizons.

Yet the physics-breaking power of the space-time ruptures is also part of their draw — sucking in scientists who want to study the role of black holes in sculpting galaxies and those searching for a unified theory of gravity. Here are the most monstrous black hole findings of the year.

Scientists spot an ultra-rare "missing link" black hole hiding in the Milky Way's center

The known black holes that populate the universe fall into two types: those up to a few dozen times the mass of the sun and their supermassive counterparts that can weigh up to 50 billion solar masses. But exactly how the former evolved into the latter is unclear, especially as there have yet to be any confirmed sightings of black holes in their awkward intermediate phases.

Enter a new intermediate black hole candidate, which astronomers spotted inside the IRS 13 star cluster, just a tenth of a light-year from Sagittarius A*, the supermassive black hole at the heart of the Milky Way galaxy. If scientists can confirm its existence, it could give vital clues to how black holes evolve.

A feasting supermassive black hole is consuming material 40 times faster than should be possible

This year, scientists found another clue to how supermassive black holes grow to their unimaginable scales, in the form of the gluttonous monster LID-568.

The James Webb Space Telescope spotted the black hole as it appeared just 1.5 billion years after the Big Bang, and it was gobbling material 40 times faster than its theoretical feeding limit (called the Eddington limit). The discovery could explain why so many giant black holes appear so early in the universe's history.

"Impossible" black holes discovered by the James Webb telescope may finally have an explanation

The finding about LID-568's feeding frenzy was far from the last word on early supermassive black hole formation. Theoreticians also proposed how black holes came to be seeded across the universe without, as they typically do today, emerging from dead stars: by rapidly collapsing pockets of gas that formed primordial black holes.

Most of these tiny singularities evaporated, according to the new hypothesis, but the ones that survived gorged and merged at a breakneck pace to reach their enormous scales.

Tiny black holes could be hollowing out planets and zipping through our bodies

Another theoretical proposal about primordial black holes also made waves this year: the suggestion that they might still exist. Perhaps they're hollowing out planets and zipping through our bodies and buildings, leaving only microscopic traces.

If bits of tiny black holes swarming across the cosmos can be found, they would be immediate candidates for most of the missing matter that seems to exert a gravitational pull yet barely interacts with light.

Biggest black hole jets ever seen are as long as 140 Milky Ways

Some black holes spew infalling matter out again, forming gigantic, near-light-speed plasma jets that can extend for hundreds of light-years. But one black hole jet pair astronomers spotted — named Porphyrion, after a giant in Greek mythology — really took the cake: At 23 million light-years in length, the pair is as long as 140 Milky Way galaxies laid end to end.

Black hole "blowtorch" is causing nearby stars to explode

Black hole jets aren't just incredible features. They're a powerful — yet still mysterious — force for the cosmic monsters to shape the wider universe. For the first time, researchers have observed a black hole jet causing stars in its vicinity to burst in explosions called novas.

Because the stars weren't directly hit by the beam, exactly how the jet is causing the stars to pop is unknown. By searching for answers, astronomers could gain a better understanding of how black holes affect even extremely distant surroundings.

Astronomers discover why some black holes have a "heartbeat"

While feeding, black holes can heat up their "food" to immense temperatures to release enormous X-ray flares that last millions of years. But inside these flares lurks another, strange signal: a regular pulse of light that resembles a heartbeat. By studying one of the flares, astronomers now think they have an explanation for black hole heartbeats: They're produced by shock waves that ripple through black holes' food as they feast.

Event Horizon Telescope reveals why our galaxy's black hole is spinning so weirdly

Our galaxy's central black hole, Sagittarius A*, is a gargantuan tear in space-time that is 4 million times the mass of the sun and 14.6 million miles (23.5 million kilometers) wide. But these are pretty standard proportions for a black hole of this scale. What is unusual about Sagittarius A* is that it's spinning surprisingly fast and it's out of kilter with the rest of the Milky Way.

This year, using the Event Horizon Telescope, which in 2022 captured the first image of our galaxy's black hole, scientists found the answer: Sagittarius A* was likely born from a gigantic collision between two giant black holes, and its lopsided rotation is a key sign of its violent origins.

Scientists spot the first black hole "triple" system

Many black holes exist in binary systems, orbiting a star companion, but researchers have now spotted one orbited by two stars, making it the first black hole triple system ever seen. Beyond creating an entirely new category in its own right, the discovery has serious implications for black hole formation.

Black holes that exist in binary systems are typically thought to have emerged from the gravitational collapse of a star. But astronomers say this triplet could offer firsthand evidence of black holes directly collapsing from gas clouds.

Dormant black hole roars to life

Black holes are typically either active and consuming material around them, or dormant because they have already swallowed everything in their midst. It's rare to see black holes shift between the two states. But astronomers have now spotted a black hole that's waking up after a long slumber.

The reasons for the black hole's reactivation remain unclear, but astronomers hypothesize that it may have begun to capture new material. Alternatively, the light coming from near the space-time singularity star that it has snared and exploded.

A crisis some call a "silent pandemic" is sweeping the globe. It's grown steadily and stealthily, without drawing as much attention as viral outbreaks that have flared up over the same period. The culprit driving this pandemic: multidrug-resistant bacteria, also known as superbugs.

Superbugs show extensive antibiotic resistance, meaning drugs that would historically cure people of the infections stop working. Bacteria develop this resistance over time as they evolve, and they can easily share that resistance with other microbes, thus compounding the issue.

Scientists are working to develop alternatives to antibiotics, as well as employing strategies to make existing drugs work better. Live Science has been documenting their efforts, as well as the emergence and spread of new superbugs, over the past year. Here are 10 of our most important and interesting superbug stories from 2024.

Related: 10 of the deadliest superbugs that scientists are worried about

Killing CRAB

A newfound antibiotic can kill carbapenem-resistant Acinetobacter baumannii, or CRAB, a superbug that's resistant to most existing drugs. The drug represents a novel class of antibiotic, and it slays bacteria by messing with the machinery they need to build their outer membranes. The mechanism is highly selective, meaning the drug works only on A. baumannii. This narrow target makes the drug less likely to pressure other bacterial species into developing resistance, scientists reported.

"Hypervirulent" superbug is spreading

New strains of a superbug called hypervirulent Klebsiella pneumoniae (hvKp) have been detected in 16 countries, including the United States. Classic versions of the microbe were already a big problem, especially among people with weakened immune systems in health care settings. But now, hvKp is becoming more widespread — it can cause severe, fast-progressing infections, even in people with robust immune systems.

Lingering bugs in the body

A study found that two concerning superbugs — namely, various antibiotic-resistant strains of K. pneumoniae and E. coli — can linger in the human body for up to five and nine years, respectively. This puts the carriers of these bacteria at risk of recurrent infection and of exposing other people to the same microbes. In the meantime, the superbugs also have a chance to share their antibiotic-resistant genes with other bacteria.

C. diff evolution

The superbug Clostridioides difficile (formerly called Clostridium difficile) — or C. diff, for short — can quickly evolve resistance to one of the main drugs used to treat it. However, this evolution comes at a cost, scientists found. Once the microbe becomes resistant, it seems to grow less efficiently. Understanding the nuances of how C. diff adapts to different antibiotics could help scientists develop new treatments that are harder for the bug to resist.

Kryptonite for superbugs?

Could there be a way to transform superbugs back into average microbes that are vulnerable to antibiotics? Scientists are exploring strategies to do just that, evolutionary biologist Tiffany Taylor explained. For example, some researchers hope to use phages — viruses that attack bacteria — to deliver genes into superbugs that reverse their antibiotic resistance. Other labs are finding strategies to stop bacteria from forming tough-to-treat "biofilms," or from making certain proteins. Together, these efforts are intended to keep our current antibiotics working as well as they can, for as long as possible.

"Phage whisperer"

As the problem of antibiotic resistance continues to swell, some scientists are hunting for alternative treatments for bacterial infections. One of these treatments, called phage therapy, actually existed before the discovery of antibiotics but fell to the wayside once the essential drugs rose to prominence. In this excerpt of her latest book, science journalist Lina Zeldovich highlights some early pioneers of phage therapy, which uses viruses to fight bacteria.

Related: Superbugs are on the rise. How can we prevent antibiotics from becoming obsolete?

How quickly can resistance emerge?

How quickly can a given bacterium evolve resistance to antibiotics? Notably, evolution rates vary among bacterial species, along with other factors that shape their inner workings. But generally, bacteria can pick up the mutations needed to become resistant instantaneously or within a few days. In an infected person, a whole population of bacterial cells can gain resistance very efficiently because once one cell has a resistance gene, it can share that gene with its neighbors.

Deep-sea antibiotics

The next generation of antibiotics may be lurking in the deep sea, scientists reported. Researchers found that Arctic Ocean microbes called Actinobacteria make unique antibiotic compounds. These compounds showed promise in lab-dish experiments with "enteropathogenic" E. coli, which causes intestinal infections. But it will be some time before we know if these compounds will be clinically useful.

Unpacking "heteroresistance"

Some scientists are investigating a unique form of antibiotic resistance called "heteroresistance." Heteroresistant microbes can initially be vulnerable to antibiotics, but when exposed to a certain dose, they suddenly "turn on" their resistance. These bacteria may thwart a patient's treatment, requiring them to switch antibiotics or stay in the hospital longer. And we don't yet have good ways to test for the germs ahead of time, microbiologist Karin Hjort told Live Science.

New fungal infection in China

Scientists in China reported the identification of a new fungal infection that had never been seen in humans. While bacteria that are resistant to antibiotics are a growing threat, so too are fungi that are impervious to antifungal drugs. In this case, the fungus — Rhodosporidiobolus fluvialis — showed resistance to several first-line antifungals when grown in the lab at temperatures similar to those of the human body. The study's findings suggested that, as climate change progresses, R. fluvialis and similar yeasts could evolve to gain more resistance.

Ever wonder why some people build muscle more easily than others or why freckles come out in the sun? Send us your questions about how the human body works to community@livescience.com with the subject line "Health Desk Q," and you may see your question answered on the website!

Since its launch on Christmas Day, 2021, the James Webb Space Telescope has proven its worth year after year. 2024 is no exception. Here are just five times the ultrapowerful telescope has reshaped our understanding of the universe.

Big galaxies

The James Webb telescope was designed, in part, to hunt for the universe's first galaxies. Those galaxies are so distant from us that the expansion of the cosmos has shifted their light into the redder, or infrared portion, of the electromagnetic spectrum.

Astronomers have used the observatory to find those ancient galaxies, and what they found, time and again, were galaxies that were larger and brighter than we expected them to be. What's at stake here is our understanding of galaxy formation. The early universe appears to be a much more active place than we thought.

Galaxies appear and grow very quickly, within only a few hundred million years. Cosmologists don't understand how the processes that grow galaxies could evolve so rapidly, and astronomers hope that future James Webb telescope observations will reveal the clues needed to solve that riddle.

Big black holes

JWST spotted some gigantic black holes this year. In May, astronomers witnessed two massive beasts, each weighing roughly 50 million times the mass of the sun, mid-collision when the cosmos was about 740 million years old.

Big black holes in the early universe are even harder to explain than big galaxies. That's because the only known way black holes form is through the deaths of massive stars, which leave behind black holes weighing up to a few times the mass of the sun. From there, those tiny seeds have to consume surrounding material at an astounding rate, and merge quite frequently, to reach supermassive status at such an early cosmological age.

Astronomers don't know what astrophysical processes can explain how these black holes got so big so early — but JWST could also help answer that question.

Hubble tension

In the past decade, cosmologists have lost sleep over a problem known as the Hubble tension. Different methods for estimating the present-day expansion rate of the universe, known as the Hubble rate or Hubble constant, are returning slightly different numbers.

The main difference is that measurements taken from the early universe are slightly larger than the measurements taken from the later universe. Astronomers have floated hundreds of proposals to resolve the tension, from mundane measurement errors to rewriting our understanding of dark energy.

At this time, there is no commonly accepted explanation for the tension. And this year, the James Webb telescope didn't help after confirming that yes, Virginia, the Hubble tension is very real. So…thanks?

Carbon neutral

Life as we know it requires at least five key ingredients: hydrogen, oxygen, carbon, nitrogen and phosphorus. Take one away, and the basic biochemical processes that make life possible would cease. Hydrogen was forged in the first few minutes of the Big Bang. The rest can only be made in the hearts of stars. These ingredients only make their way into interstellar space — where they can participate in the forming of new stars and new solar systems — once those stars die.

A planet like Earth, rich enough in those elements to make life possible, is the product of multiple generations of stellar lives and deaths spanning billions of years. So it was a surprise when astronomers used the James Webb telescope to find a cloud of carbon that formed just 350 million years after the Big Bang.

This pushes the clock way back on when life could have first appeared in the cosmos. If a large amount of carbon was present in a cloud, then the other key ingredients were likely floating around as well. And all those elements could have fashioned a planet before the universe was even half a billion years old. We don't know yet if life existed back then, but this discovery is a major clue that it was possible.

The First Generation

The James Webb telescope is an instrument of firsts: first galaxies, first black holes, first building blocks of life. But the real cosmic holy grail is to find the first stars. In the peculiar nomenclature of astronomy, the first generation of stars is known as Population III stars. No known Population III stars exist in the present-day universe, and astronomers suspect that no stars from that generation lived long.

Those stars would be much different than modern-day populations, which need heavier elements to moderate their fusion reactions. But the first generation had only primordial hydrogen and helium to work with. Those stars formed before even the first galaxies, and they introduced the cosmic dawn — the cosmos's first starlight.

Finding the first stars would be monumental, and this year, astronomers may have done it. Researchers discovered subtle hints of Population III stars in the combined light from galaxy GN-z11, a galaxy living just 430 million years after the Big Bang. Even though this galaxy existed long after the appearance of the first stars, it may retain a remnant population of those ancient sparklers. The discovery is still tentative, but if it holds up, it may go down in history as the James Webb telescope's most important discovery.

Disagreements about research results aren't often aired in the open, but this year saw its fair share of public scientific controversies.

Debates between scientists are usually confined to the pages of scientific journals, with researchers criticizing one another's work via letters and commentaries. Occasionally, though, these disputes spill out into the wider media, and they can range from squabbles over dinosaur bones to huge controversies around key archaeological artifacts.

This year, scientists argued about everything from climate change, to space junk to black holes. Here is our list of 2024's most controversial science stories.

Building world's 1st pyramid

In a preprint study published this summer, researchers proposed that ancient Egyptians built the world's first pyramid — the 4,700-year-old Step Pyramid of Djoser, which sits on Egypt's Saqqara plateau — using a "modern hydraulic system" powered by a long-gone branch of the Nile River. The system comprised a dam, a water treatment plant and a hydraulic freight elevator, the researchers suggested, enabling workers to deliver heavy construction materials to the pyramid building site.

The proposed infrastructure addresses long-standing questions about how ancient Egyptians erected the Step Pyramid of Djoser, which contains 11.6 million cubic feet (330,400 cubic meters) of stone and clay, before the advent of large machinery like bulldozers and cranes. Study lead author Xavier Landreau told Live Science the hydraulic system was "a watershed discovery," but another expert wasn't so sure about the findings.

Julia Budka, an archaeologist specializing in ancient Egypt at Ludwig Maximilian University of Munich in Germany, told Live Science that "scientifically, their hypothesis is not proven at all." Budka added: "My biggest concerns about the study are that no Egyptologists or archaeologists were directly involved and that the authors actually question the use of the Djoser Pyramid as a burial site." (Peer-reviewed research shows the pyramid was in fact used as a burial site.)

Black hole image

A groundbreaking picture of Sagittarius A*, the supermassive black hole that sits at the center of the Milky Way, caused a stir this year, with a study published online in May claiming the image displays important errors. The photo, which was taken with the Event Horizon Telescope (EHT) in 2017 and released in 2022, is the first ever image of our galaxy's central black hole, located 26,000 light-years from Earth.

The image shows an orange, donut-shaped ring of gas against a pitch-black background — but researchers say the ring is distorted due to the way the data for the image were stitched together. The ring should be more elongated than it appears in the image, the researchers said, and the eastern half should be brighter than the western half.

"We hypothesize that the ring image resulted from errors during EHT's imaging analysis and that part of it was an artifact, rather than the actual astronomical structure," study lead author Makoto Miyoshi, an astronomer at the National Astronomical Observatory of Japan, said in a statement at the time.

The EHT team responded to the claims in November saying that their methods were extensively verified, and their results consistent over two days of observations. The team pointed out inconsistencies in the revised image, arguing that Miyoshi and colleagues mistook "the biases in their own methodology as demonstrations of biases" in the original EHT methods.

Global warming's beginning

A study published early this year found Earth is on course to reach 3.6 degrees Fahrenheit (2 degrees Celsius) of warming relative to preindustrial levels by the late 2020s — more than a decade earlier than current projections. Global warming of 2 C is considered a critical threshold to prevent the worst effects of climate change; warming beyond this would greatly boost the likelihood of extreme weather and other destructive impacts.

The study authors said in a news conference that their results mark "a major change to the thinking about global warming," because they bring forward the advent of human-made climate change by four decades, meaning scientists have been underestimating the level of warming all along. The United Nations' Intergovernmental Panel on Climate Change estimates that global warming began around 1900, but the recent study says the start date is more likely to have been in the 1860s.

The authors based their results on climate indicators found in old skeletons of sponges from the Caribbean Sea. But other experts criticized the findings, saying the authors wrongly extrapolated from highly local data to draw conclusions about the whole world. "The study fails to support its global claims with robust evidence, and it fails by a huge margin," Jochem Marotzke, a professor of climate science and director of the Max Planck Institute for Meteorology in Germany, told Live Science.

"Skepticism is warranted here," Michael Mann, director of the Penn Center for Science, Sustainability and the Media, told Live Science. "It honestly doesn't make sense to me."

Weakening Earth's magnetic field

Defunct satellites that burn up as they enter Earth's atmosphere could be releasing dust that interferes with the planet's magnetic field, according to a preprint study that attracted criticism this year. Metal pollution from falling space junk may theoretically create an invisible conductive shell around Earth, weakening the magnetosphere — the bullet-shaped field around Earth that stretches roughly 39,800 miles (64,000 kilometers) above our planet's surface.

The metal pollution, a problem that is being made worse by the unchecked expansion of commercial satellites orbiting Earth, could slice the magnetosphere in half and lead to "atmospheric stripping" down the line, study author Sierra Solter-Hunt, who was then a doctoral candidate at the University of Iceland, told Live Science. Although this is a worst-case scenario, the findings are "really, really alarming," Solter-Hunt said.

Some scientists praised the study for highlighting potential issues arising from spacecraft dust, but others said the results were too speculative or based on flawed assumptions. "Even at the densities [of spacecraft dust] discussed, a continuous conductive shell like a true magnetic shield is unlikely," John Tarduno, a professor of physics and astronomy at the University of Rochester in New York, told Live Science.

Nevertheless, space junk pollution "is not an issue to be ignored," said Fionagh Thompson, a research fellow at Durham University in the U.K. "There is a need to step back and view this as a completely new phenomenon."

Baby T. rex or tiny dino?

A study in January weighed in on a long-standing debate over a set of dinosaur fossils that could belong either to a young Tyrannosaurus rex or to a distinct species called Nanotyrannus lancensis. The study supported the Nanotyrannus hypothesis, based on growth rings on the fossils, and claimed to snuff out the opposing side of the dispute once and for all — but other experts still weren't convinced.

The study authors found that growth rings were closely packed toward the outside of the bones, which is inconsistent with the rapid growth of a dinosaur, and therefore refutes the juvenile T. rex hypothesis, they said. "If they were young T. rex they should be growing like crazy," lead author Nicholas Longrich, a paleontologist and senior lecturer at the University of Bath in the U.K., said in a statement at the time. Instead, the bones showed a pattern consistent with slowing growth, Longrich said.

But some experts remained resolutely team T. rex. "The authors don't seem to have a solid grasp on growth variation in tyrannosaurs," Thomas Carr, a vertebrate paleontologist and an associate professor of biology at Carthage College in Wisconsin, told Live Science. Others said they will sit on the fence until fossils come to light that belong to either a fully adult Nanotyrannus or a young T. rex that definitely isn't Nanotyrannus — at which point comparison work could settle the question once and for all.

Alexander the Great's lost tunic?

A scrap of cloth discovered decades ago in a royal tomb belonged to none other than Alexander the Great, according to a controversial study published in October. Located in Greece, the tomb is generally believed to hold the remains of Alexander's father, Philip II, but the study argues it actually belongs to Alexander's half-brother, Philip III. Therefore, the cloth inside was once part of a sacred tunic worn by Alexander that, after his death, was passed on to Philip III and accompanied him to his grave, the author claimed.

The study's conclusions are based on multiple lines of evidence — such as the art on the tomb's walls, studies of the skeletons found inside and ancient records of garments worn by different kings — but the findings sparked mixed reactions from experts. Some researchers said there is no evidence to support the idea that the cloth formed part of a tunic, while others noted that the author of the study never actually saw the piece of material, discrediting the paper's conclusions.

Another group of researchers, meanwhile, thought the case for the cloth being Alexander's lost tunic was strong.

AI fingerprint-matching tool

A new technique to match fingerprints from separate digits belonging to the same person sparked controversy at the beginning of 2024. It's long been suspected that connecting prints from different digits could help solve criminal cases, but forensic methods so far haven't been able to do so accurately, only reliably linking fingerprints from the same digit.

Researchers used artificial intelligence (AI) to develop a tool that can connect different fingerprints left by the same person 77% of the time, based on similarities between the angles of arches, whorls and loops on each finger. The study in which they detailed their methods was rejected by several journals but was eventually published, receiving mixed reactions from other experts.

Simon Cole, a professor of criminology, law and society at the University of California, Irvine, said the study was "overhyped" and only had "rare and limited use," given that law enforcement routinely takes prints from all 10 digits and can match prints simply by looking at records.

Ralph Ristenbatt, a criminalist and assistant teaching professor of forensic science at Pennsylvania State University, argued the technique could prove useful in certain cases. But more work is needed until the AI tool is accurate enough to be rolled out and used in a court of law.

Megalodon misrepresented?

A new analysis of megalodon fossils published in January found that the long-extinct, supersized sharks looked nothing like researchers previously thought. Reconstructions to date indicated that megalodons (Otodus megalodon) measured around 52 feet (16 meters) long and resembled great white sharks (Carcharodon carcharias), but this body shape "looked very awkward," according to the authors of the new study.

The anatomy of megalodon has remained somewhat elusive because shark skeletons are made of cartilage rather than bone, and therefore don't preserve well as fossils. Scientists mostly only had fossilized teeth and vertebrae to work with, so they often used great white sharks as models to establish what megalodon looked like.

The analysis in January found megalodons were much slimmer and longer than great whites, with a body plan closer to that of a shortfin mako shark (Isurus oxyrinchus). The evidence suggested the meg may have reached 66 feet (20 m) long or possibly slightly more, the authors told Live Science. But other researchers who had previously examined megalodon fossils weren't convinced by the findings.

According to them, the analysis used "circular logic," where an argument uses the assumption that its conclusion is correct to support itself. "The 'elongated body' interpretation is based on a single observation, a comparison with a single analogue, and lacks any statistical tests to support its hypothesis," Jack Cooper, a researcher at Swansea University in the U.K., Catalina Pimiento, also of Swansea University, and John Hutchinson from the Royal Veterinary College in London told Live Science. The study is also impossible to fully verify as the authors held back crucial data, the researchers said.

From orcas wearing salmon hats to April's total solar eclipse, it's been a big year for science news. We've brought together the five stories that you loved the most in 2024, starting with a cosmic conundrum that could rewrite everything we thought we knew about the universe.

We've been wrong about the universe

At the start of the year, the James Webb and Hubble space telescopes teamed up to confirm one of the most troubling conundrums in physics — that the universe is expanding at different speeds depending on where we look.

The phenomenon was first observed by Hubble in 2019 and again by James Webb in 2023, but scientists hoped there might have been an error in the measurements. But on Feb. 6, a triple-check confirmed these discrepancies, throwing what we thought we knew about the universe into question.

"With measurement errors negated, what remains is the real and exciting possibility we have misunderstood the universe," lead study author Adam Riess, professor of physics and astronomy at Johns Hopkins University, said in a statement.

Discover more James Webb highlights from 2024

—James Webb telescope solves 20-year-old Hubble conundrum — and it could finally explain why the universe's oldest planets exist

—James Webb telescope finds carbon at the dawn of the universe, challenging our understanding of when life could have emerged

—James Webb telescope sees 'birth' of 3 of the universe's earliest galaxies in world-1st observations

Spiders on Mars

More extraterrestrial excitement was stirred towards the end of April, when the European Space Agency (ESA) photographed hordes of spindly, spider-like markings littered across Mars' south polar region, around a mysterious formation known as Inca City.

The black clusters appeared to have tiny, spoke-like legs, reminiscent of a huddle of baby spiderlings. However, ESA revealed that the ”alien arachnids” were actually a seasonal geological feature born from layers of melting carbon dioxide ice.

Indeed, a few months later, researchers were actually able to recreate these strange spider-like structures on our own planet.

Discover more space highlights

—Fallout from NASA's asteroid-smashing DART mission could hit Earth — potentially triggering 1st human-caused meteor shower

–Astronauts stranded in space due to multiple issues with Boeing's Starliner — and the window for a return flight is closing

—No, you didn't see a solar flare during the total eclipse — but you may have seen something just as special

Giant 200-million-year-old 'sea monster' found on beach

Also in April, scientists unearthed the remains of what they believe to be the largest marine reptile ever discovered, on a beach in Somerset in the U.K.

Piecing together the remaining bone fragments from the 200-million-year-old Triassic predator, the team estimated that the living animal would have been about 82 feet (25 meters) long. This smashes the previous record for the largest marine reptile — Shonisaurus sikanniensis, which would have measured around 69 ft (21 m).

The researchers named the newly discovered fossil Icthyotitan severnensis, which means giant lizard fish of the Severn, after the Severn Estuary where it was found.

Discover more animal highlights

—Hidden DNA found in blue whales reveals they've been mating with other species — and their hybrid offspring

—Orcas start wearing dead salmon hats again after ditching the trend for 37 years

—Ants perform life saving operations — the only animal other than humans known to do so

Earth's inner core is slowing down

Since 2014, scientists have noticed a mysterious trend deep inside our planet — Earth's solid inner core is spinning unusually slowly.

The moon-size chunk of solid iron and nickel at the center of our planet is surrounded by an outer layer of swirling liquid iron, and it is this outer core — combined with gravitational forces from the overlying mantle — that appears to be slowing down the inner core's rotation.

But what does this mean for us? So far, we can only speculate, but researchers say it could potentially lengthen days on Earth — albeit only by a couple of milliseconds.

Discover more planet earth highlights

—Never-before-seen shapes up to 1,300 feet long discovered beneath Antarctic ice

—Key Atlantic current could collapse soon, 'impacting the entire world for centuries to come,' leading climate scientists warn

—'Superstructure' bigger than Idaho has been growing on the seafloor by Fiji since the dinosaur age

700-year-old child sacrifice

In early November, archaeologists uncovered a 700-year-old burial mound in Peru containing the remains of 76 sacrificed children and two adults. Each had had their chest cut open, likely to gain access to their hearts.

The bodies were accompanied by silver, gold, ornaments and the shells of a tropical marine mollusk called a Spondylus — objects that the researchers say were "more valuable than gold" for the local community at the time.

The shells also hint that the sacrifice victims may have come from a conquered northern territory and been brought to the site of the burial to work on the land. The researchers say the children may have been sacrificed in an effort to "energize" the agricultural fields.

Discover more archaeology highlights

—2,600-year-old inscription in Turkey finally deciphered — and it mentions goddess known 'simply as the Mother'

—Pompeii victims aren't who we thought they were, DNA analysis reveals

—'Simply did not work': Mating between Neanderthals and modern humans may have been a product of failed alliances, says archaeologist Ludovic Slimak

Earth has existed for 4.54 billion years, and during that time, our planet has undergone a number of violent transitions. This makes it difficult for researchers to find out what happened during Earth's early history, as most of the evidence was destroyed eons ago.

However, scientists have discovered ancient rocks scattered throughout the globe. These remnants provide a glimpse into Earth's infancy and help scientists trace our planet's development. Here are some of the oldest rocks ever discovered and the insights they provide about our home planet.

Related: Did plate tectonics give rise to life? Groundbreaking new research could crack Earth's deepest mystery.

The Jack Hills, 4.4 billion years old

The Jack Hills, in Western Australia, contain tiny traces of rock that are older than the hills themselves. The 50-mile-long (80 kilometers) ridge contains crystallized minerals called zircons dating to 4.4 billion years ago, making them the oldest Earth materials ever found. Zircon crystals are durable; they can survive even when the rocks around them are destroyed, eroded or recycled back into Earth's middle layer. Zircons contain radioactive uranium, which decays very slowly, thereby helping geologists accurately date the crystals. Some zircons in the Jack Hills, which date to around 4 billion years ago, also hint that early Earth had fresh water just 600 million years after it formed.

Nuvvuagittuq Greenstone Belt, 3.8 billion to 4.3 billion years old

The Nuvvuagittuq Greenstone Belt in northern Quebec may hold the world's oldest preserved rock. A greenstone belt is a long area that mainly contains metamorphosed sedimentary and volcanic rocks and is the remains of an ancient ocean basin. The exact age of Nuvvuagittuq's rocks is controversial: Some studies used zircons to find a minimum age of 3.8 billion years old, but a later study that looked at parts of Earth's primordial crust suggested the rocks' maximum age was 4.3 billion years old, meaning it dates to the Hadean (4.6 billion to 4 billion years ago). Subsequent studies continue to debate the belt's exact age. Some researchers have also suggested the belt contains evidence of Earth's earliest life — traces of bacteria dating to between 4.3 billion and 3.7 billion years ago.

Related: What's the difference between a rock and a mineral?

Acasta Gneiss, 4 billion years old

Rocks located in the Acasta Gneiss Complex in northern Canada have been dated to 4 billion years ago, making them the oldest definitively dated rocks, according to the educational platform Open Geology. Gneiss is a type of metamorphic rock that has been subjected to high temperatures and pressures deep in Earth's crust. The rock was isotopically dated, meaning scientists measured the ratio of uranium atoms that have transformed into lead.

Isua Greenstone Belt, 3.8 billion years old

The Isua Greenstone Belt in western Greenland contains some of the oldest rocks on Earth. However, Isua is also important because some researchers have argued it holds the earliest evidence of life on Earth, dating to 3.7 billion years ago. In 2017, researchers discovered what looked like tiny waves in a cross section of the surface of a rock outcrop. The researchers said the ripples are the fossilized remains of cone-shaped stromatolites — layered mounds of sediment and carbonates that build up around colonies of microbes that grow on the floor of shallow seas or lakes. However, this finding is controversial. In addition, Isua holds "chemical fingerprints" of an ancient magma ocean that bubbled over much of Earth's surface 4.5 billion years ago, soon after the planet's birth.

Barberton Greenstone Belt, 3.5 billion to 4.1 billion years old

Ancient rocks in southern Africa's Barberton Greenstone Belt contain evidence for some of the earliest known earthquakes, which occurred around 3.3 billion years ago. The rocks provide evidence of early plate tectonics. In 2021, researchers published a partial map of the belt, which revealed "a gigantic jumble of blocks" detached from where they formed, Simon Lamb, a geologist at Victoria University of Wellington in New Zealand who was involved in a later study on Barberton, told Live Science at the time. The belt also contains ancient zircons dating to between 4.1 billion and 3.3 billion years ago.

Napier Complex, 3.6 billion to 4 billion years old

The Napier Complex in eastern Antarctica holds zircons dating to around 3.6 billion years ago and just one zircon dating to 4 billion years ago. "Its significance cannot be overestimated, since it may indirectly evidence the existence of an Early Archean crustal block with a minimum age of 4 Ga [4 billion years]," researchers wrote in a 2011 study of the zircons published in the journal Doklady Earth Sciences. Crustal blocks, also known as fault blocks, are huge chunks of rock formed by tectonic and other forces.

Anshan area, 3.8 billion years old

The Anshan area in northeastern China holds the country's oldest rocks and some of the most ancient rocks in the world. Anshan is part of the 580,000-square-mile (1.5 million square kilometers) North China Craton, but the most ancient rocks cover less than 8 square miles (20 square km).

Big Bertha, 4 billion years old

In 2019, scientists discovered that one of Earth's oldest rocks has spent billions of years away from our planet and only recently returned home. Apollo 14 astronauts collected the roughly 4 billion-year-old rock, nicknamed Big Bertha, from the moon's surface in 1971. The stone contains minerals similar to granite and quartz, which are extremely rare on the moon, study co-author Alexander Nemchin, a professor in the School of Earth and Planetary Sciences at Curtin University in Australia, said in a statement. The 2019 research found that parts of the rock formed in conditions that are rare on the moon but typical on Earth. This finding suggests it formed on Earth but was knocked away from our planet by a giant asteroid impact, before settling on our celestial neighbor, according to NASA.

If you're worried about humanoid robots taking your job in 2025, rest easy. The few commercially available models are slow, ponderous and best suited to menial jobs that humans hate — think lifting a 20-pound (9 kilograms) object onto a conveyor belt.

But things are set to change. By the end of this decade, many experts think humanoid robots will have evolved — if that's the right word — into genuinely useful members of the workforce. They will likely be faster than humans, work longer hours and have higher reasoning abilities than the best AI chatbots. Per year, they will also cost less.

If you're cynical about all this, you're right to be. Up until this point, companies have made many claims they've struggled to meet. What's more, only one humanoid robot in our seven-strong list is currently on active working duty.

Despite this, it's still likely that in five years' time we will see humanoid robots on sale that combine the dexterity of Atlas, the emotional connection of Ameca, the hand skills of Phoenix, the brains of Figure 02 and the style of Optimus. Here are seven robots that pushed the boundaries in 2024.

7: Apollo, the general purpose robot

The co-founders of Apptronik worked on the NASA Valkyrie robot project in 2012 to 2013. From that star-studded heritage comes Apollo, a general purpose humanoid robot that stands 5 feet 8 inches (1.73 meters) tall.

It's "general purpose" because Apollo could just as easily look after the elderly as work in a factory, with an Nvidia partnership enabling it to use artificial intelligence (AI) to learn skills just by observing humans performing tasks. But that's the future. For now, Apollo is at the prototype stage, although Apptronik is partnering with Mercedes-Benz to test scenarios in its factories.

6: Digit, the working robot

As with so many in our list, Agility Robotics' Digit is built to carry out repetitive tasks in industrial settings such as warehouses. Very much unlike its rivals, though, this robot is already being put to work. Head to GXO Logistics' facilities at Flowery Branch in Georgia, and you'll find a tireless robot worker moving boxes weighing up to 35 pounds (16 kg) from autonomous mobile delivery units onto a conveyor belt.

However, Digit is not the most elegant of robots. The majority of its 5 foot, 9 inch (1.75 m) frame is dominated by backward-facing legs that enable it to stand close to racks, with the only concession to a more friendly design being a pair of rectangular LED "eyes" (in reality, it uses Lidar and Intel RealSense depth cameras to detect its surroundings).

5: Phoenix, the finger-clicking good robot

While other robot makers focus on speed and strength, Sanctuary AI's Phoenix is all about the fingers. In December 2024, the company revealed its robot with fingers that are so dextrous they can maneuver a 12-sided die as needed, along with having tactile pads for each finger.

Sanctuary AI focuses much of its efforts on intelligence, with the aim to build a modular robot that can add new skills via hardware and on-the-job learning. But Phoenix remains a prototype, with its only official outing so far being a week-long pilot in its native Canada, where it worked in a retail store performing tasks such as packing merchandise.

4: Figure 02, the talking robot

Much like Tesla's Optimus Bot, the Figure 02 could have stepped out of a science fiction movie. Add laser beam eyes and we'd be afraid. Until, that is, we saw this 5 foot, 6 inch (1.68 m) robot walking — or more accurately, shuffling — and talking.

Figure 02 is the only robot on our list that can talk, applying OpenAI's large language models (LLM). That means you can ask it for something to eat and it will pass you an apple, and you can talk to it just as you do ChatGPT.

With dextrous fingers — and the ability to learn from its mistakes, this is one of the most advanced humanoid robots around. However, we don't yet know when it will move out of the prototype phase.

3: Ameca, the friendly robot

Ameca, created by Engineered Arts, takes a different approach from others on this list, with realistic hands and a face that is able to express emotion. Flexible skin and realistic eyes, plus a choice of on-board or cloud-based AI, mean it can even greet you with a delighted smile and respond near-instantly to questions. Another key difference is that Ameca can't yet walk. It's designed instead to be modular, so it could be attached to wheels or even be bought (or rented) as a torso and head alone..

2: Atlas, the scary robot

Don't mess with Atlas. Made by Boston Dynamics, this 5-foot-tall (1.5 m) humanoid robot possesses amazing balance skills — it can even move (relatively) gracefully from a prone position to standing up. A Cyclops-style eye that dominates its head perhaps doesn't help its human interaction skills.

To add further to this robot's terrifying list of skills, it can run at 5.6 mph (9 km/h), jump and even perform backflips. Unlike the other robots on this list, its incredible balance also means it can negotiate tough terrain.

With AI-enhanced vision to complete tasks autonomously, and a pair of simple but flexible claw-like hands, it's easy to imagine Atlas performing a wide range of tasks. But we'll have to wait, as this robot remains in the prototype stage for now.

1: Optimus Gen 2, the slick robot

Tesla wowed attendees of its "We, Robot" evening in October 2024, with the newest generation of its stylish humanoid robot serving attendees drinks — only for it to be revealed that humans were controlling the bots' hands, which were so dextrous they could make a cocktail.

But it's only a matter of time before the combination of AI and advanced sensors mean these 5 foot, 8 inch robots, set for roll-out in Tesla factories at some point in 2025, will live up to the hype. With Tesla's deep pockets and access to cutting-edge AI, battery technology and components, we think the Optimus Gen 2 deserves to be recognized as the most complete and advanced humanoid robot around today.

Editor's Note: This story was updated on Jan. 2, 2025 at 8:45 a.m. EST to remove reference to the Agility robot's price. The company has not yet published prices.

Sometimes science needs to go big. From telescopes spanning the globe to particle accelerators that would take over 24 hours to walk around, these experiments are among the largest ever conducted.

Gravitational wave hunting

Ripples in the gravitational field of the universe, known as gravitational waves, are remnants of massive galactic events such as black hole collisions and merging neutron stars. These waves may even record echoes of the Big Bang. To detect them, scientists need big equipment, such as the Laser Interferometer Gravitational-wave Observatory (LIGO).

LIGO consists of two large instruments, each with two 2.5-mile-long (4 kilometers) arms. The instruments are in Washington state and Louisiana, approximately 1,900 miles (3,000 km apart). The arms are laser interferometers, arranged in L shapes. A single laser beam is split in half, with each half sent down one of the arms. At the end of each arm is a set of mirrors, which bounce each half laser beam around a few hundred times and then back up the arms so they reunite.

By investigating the interference pattern — the way the peaks and troughs of the light waves combine — scientists can determine if a gravitational ripple happened during the experiment. If so, they can study it in detail. The larger the arms, the more sensitive the instrument, which is why LIGO boasts the longest laser interferometers ever built.

LIGO has detected all manner of mysterious galactic phenomena, from a merger between a neutron star and (probably) a superlight black hole to multiple collisions between neutron stars. (It has also detected a flock of ravens pecking on icicles at the Washington facility — an observation with fewer implications for the dynamics of the universe.)

Related: To hunt gravitational waves, scientists had to create the quietest spot on Earth

World's largest atom smasher

To study the very small, scientists sometimes have to use very big instruments. They don't come bigger than the Large Hadron Collider (LHC), the world's largest particle accelerator. Run by CERN, the European Organization for Nuclear Research, this 16.7-mile-diameter (27 km) ring is studded with four detectors, known as ATLAS, CMS, ALICE and LHCb. Befitting its location, the 7,700-ton (7,000 metric tons) ATLAS is the largest particle detector ever built. The instrument measures a wide range of subatomic particles created when scientists zap particle beams at one another at high speed, creating collisions that throw off elusive elementary particles like the Higgs boson.

The LHC boasts over 10,000 tons (9,000 metric tons) of iron in its magnetic systems and enough niobium-titanium cable to stretch to the sun and back over six times and then between Earth and the moon another few times. It's also the largest, coldest refrigerator on Earth, because the magnets must be kept at minus 456.25 degrees Fahrenheit (minus 271.25 degrees Celsius), slightly colder than outer space.

Miniature Amazon rainforests

By pumping tons of carbon dioxide (CO2) into the atmosphere each year through the burning of fossil fuels, humanity is performing an extremely large-scale — and very uncontrolled — experiment. In the Amazon rainforest, researchers are trying to get a handle on the implications of those greenhouse gases in a large experiment of their own.

The project, called AmazonFACE, aims to amp up the carbon dioxide concentration in parts of the world's largest tropical forest basin to understand the impacts of elevated CO2 on the "lungs of the planet."

FACE stands for "Free-Air Carbon Dioxide Enrichment." The experiment consists of 12 observational arrays in six 98-foot-diameter (30 m) plots: three at ambient carbon dioxide concentrations and three at higher concentrations. The highest concentration — 615 parts per million — is predicted to be reached by the 2070s under a middle-of-the-road pathway to climate mitigation in which countries make slow and uneven progress toward sustainability.

Each plot contains around 400 plant species and many more specimens of fungus and soil microbes — a full ecosystem. As carbon dioxide increases, plants photosynthesize more quickly and release less water from their leaves, explained Beto Quesada, executive manager of the project and a researcher at the National Institute for Amazonian Research. This could help protect the forest from the impacts of climate change, which is expected to bring drought to the Amazon region.

But the balance between these two processes and the tipping point between a healthy forest and a collapsing ecosystem are unknown, said David Lapola, the project's scientific coordinator and a researcher at the Center for Meteorological and Climatic Research Applied to Agriculture of the University of Campinas (UNICAMP) in Brazil.

"We'll be trying to solve one of the biggest uncertainties with regard to the future of the Amazon forest in light of climate change," Lapola told Live Science.

The researchers will measure the impact of the extra CO2 on plant physiology, including whether plants in a carbon-rich atmosphere add temporary structures, like leaves, or more permanent features, such as wood. This is important to study because wood locks up carbon for centuries, whereas carbon used to grow leaves reenters the environment within a year or two. The experiment is expected to run for at least a decade.

"It is an ecosystem-scale experiment," Quesada said, "but it's much more than that. It goes to the social, economical and environmental impacts that the loss of the rainforest will have."

A truly massive carbon capture facility

According to the Intergovernmental Panel on Climate Change , humanity doesn't just need to stop releasing carbon dioxide into the atmosphere to avoid raising the global temperature more than 1.5 C (2.7 F) above preindustrial levels. We also have to pull carbon back out of the air.

By 2050, 6 to 10 gigatons of carbon equivalent need to be removed to avoid hitting the warming threshold set by the Paris Agreement. There are many options for carbon sequestration, such as capturing industrial waste streams and burying biomass. But the first-ever commercial-scale marine carbon-capture facility is aiming to remove carbon right from the ocean.

The ocean naturally takes up carbon from the atmosphere, but it can't absorb it fast enough to make a climatic difference on the scale of a human life span. The carbon-capture company Equatic is aiming to accelerate that timeline.

"Equatic's commercial plant takes five minutes to remove one tonne of carbon by pumping seawater in, running an electrical current through, and then contacting the seawater with a stream of air from the atmosphere," Edward Sanders, Equatic's chief operating officer, told Live Science in an email. "An equivalent area of open ocean takes 12 months to remove that one tonne of carbon."

The chemical process that removes the carbon from the seawater also creates hydrogen, a chemical that's for many industries and can be burned as fuel to power 40% of the energy costs of the carbon-capture process. The carbon is then sequestered as bicarbonate, the same material found in seashells, which will keep the carbon out of the atmosphere for up to 10,000 years. This bicarbonate can be put back in the sea or be used in fertilizers. It can also serve as a building material in coastal restoration, Sanders said.

Similar experiments have been done on a pilot scale, but Equatic's facility in Quebec will aim to sequester 120,700 tons (109,500 metric tons) of carbon per year starting in 2027. It will be the first commercial-scale attempt to make a dent in the greenhouse gas overload in the atmosphere via the oceans.

A world of babies

How do babies learn language? When do they understand gestures? Are they hardwired to imitate adults? All of these questions are tough to answer, because babies are challenging research subjects, prone to crying and unexpected naps.

The difficulty of recruiting busy, exhausted parents and their often-uncooperative infants to do research studies led to the birth of ManyBabies. This global collaboration of researchers from over 50 nations pools smaller-scale studies of infant development into large sample sizes — often thousands of babies.

The research collaboration has found that infants really do prefer baby talk to adult-style speech, suggesting that the natural tendency to coo about a baby's toesie-woesies is an evolutionary adaptation that helps them learn language. Researchers are now studying how babies develop an understanding of other people's beliefs — a skill known as theory of mind — and trying to figure out when they learn to apply abstract rules to situations. They're also developing new methods, such as eye-tracking technology and noninvasive brain imaging techniques, to find out what infants are learning.

A city-size chunk of Antarctic ice

Neutrinos are often called "ghost particles" because the nearly massless particles barely interact as they pass through matter. Because they rarely perturb other matter, they're difficult to detect. But finding neutrinos from distant cosmic sources can be a way to observe and analyze high-energy environments such as pulsars, supernovas and black holes.

"We need a very big target, such as a billion tons of material, to have a fighting chance to — once in a while — catch some of them," said Albrecht Karle, a professor of physics at the University of Wisconsin-Madison.

Those billions of tons of material come from a cubic kilome ter of ice at the South Pole. Karle is the associate director of science and instrumentation at the IceCube Neutrino Observatory, which is remarkable in both its size and remoteness. IceCube consists of a series of optical detectors on strings, running through holes drilled 4,800 to 8,000 feet (1,450 to 2,450 meters) into the Antarctic ice.

When a neutrino interacts with the ice, it creates other particles that emit tiny flashes of light. The sensors detect this light and can measure its wavelength to reveal the flavor of neutrino and its source. (That's why a transparent medium, such as ice, is important, Karle told Live Science — the material needs to be clear for the light to be detectable.)

IceCube data has allowed scientists to make the first map of the Milky Way using matter, not just light. The observatory has also revealed strange, high-energy cosmic rays with no easy explanation. And Karle and his colleagues have plans to go even bigger. They're currently drafting a plan for IceCube Gen-2, which would expand the current observatory to eight times its current size, with a 200-square-mile (500 square kilometers) radio detector array to amplify incoming neutrinos. This would massively increase the sensitivity of the detector and allow better classification of the neutrinos that pass through it, Karle said.

A globe-spanning psychology study

The COVID-19 pandemic was its own global experiment, albeit one with a massive number of uncontrolled variables. Psychologists took advantage of this shared global experience with some of the largest psych studies of all time.

One, with almost 50,000 participants, found that people with a stronger national identity responded more cooperatively with public health efforts. Across 67 countries, people with a stronger feeling of identification with their nation were more likely than those with a weaker sense to stay put during quarantine, to support public health policies, and to say they engaged in social distancing and stricter physical hygiene after the onset of the pandemic. National identity is about a sense of collective belonging and mutual cooperation, the authors noted. This is different from beliefs about national superiority, which is a belief that one's country is better than others.

"These results are consistent with the social psychological literature on the benefits of identifying with one's social groups," the authors wrote. "They also underscore a potential benefit of [national identity], which might be salient during a national or global health crisis."

Another major COVID-era study, with nearly 27,000 participants, found that messages emphasizing autonomy encouraged adherence to social distancing recommendations. The study tested different social distancing messaging strategies across 89 countries and found that those that focused on personal autonomy and the value of thoughtful choices were more effective than messages that emphasized shame and pressure.

A centuries-long plant experiment

Small in size but big in duration, Michigan State University botanist William James Beal's seed viability experiment has been running continuously since 1879. The goal of this experiment is to find out how long seeds of different plants can lie dormant before sprouting. To find out, Beal buried bottles of seeds from 23 different plants 3 feet
(0.9 m) deep in an undisturbed (and secret) location so they could not sprout. He started unearthing bottles in five-year increments — a gap that was eventually stretched to every 10 years.

Incredibly, the experiment is still running — and now, researchers are stretching the gap between bottle openings to 20 years, because seeds just keep sprouting. The last bottles were opened in 2021, and the next set will get their time to shine in 2040. The findings have implications for plant evolution and seed germination and might be useful for understanding the process of habitat restoration and seed banking, or saving seeds for potential use in the distant future.

The plan is to keep the experiment running until 2100, according to Michigan State. Will that be enough time to find the maximum age any of their seeds can sit before sprouting? Probably not; plants have sprouted from seeds up to 2,000 years old.

China's monstrously huge radio telescope

China's Five-hundred-meter Aperture Spherical Telescope (FAST) array is the world's largest single-dish radio telescope, at 1,640 feet in diameter. Holding up the dish are 328-foot (100 m) steel towers and 6,670 cables. Now, a new phase of construction is adding 24 131-foot (40 m) movable radio telescopes to the facility.

The array sits in a natural depression called Dawodang in the rugged topography of China's Guizhou province. This shields it from electromagnetic interference from human sources and increases its sensitivity to cosmic radio signals. The goal, according to the Chinese Academy of Sciences (CAS), is to use the telescope's sensitivity to conduct large-scale surveys of the universe.

FAST started operating at full capacity in 2020 and has already discovered more than 200 pulsars, which are rotating neutron stars that emit regular pulses of electromagnetic radiation. These include the pulsar PSR J0318+0253, which, at 4,000 light-years away and with a rotation period of less than 10 milliseconds, is one of the faintest radio millisecond pulsars ever found, according to CAS.

A telescope network that spans most of the world

What could you see with a telescope the size of the world? Well, the black hole at the heart of the Milky Way, for one thing.

The Event Horizon Telescope (EHT) is a network of radio telescopes stretching from Greenland to the South Pole (north to south) and from Spain to Hawaii (east to west). The exact number of observatories in the EHT shifts with time (it was 11 as of 2021), and new telescopes will be added in the future — including one planned for the Canary Islands.

These observatories work together to detect faint radio signals associated with black holes. This collaboration generated the first-ever view of a black hole, including the contours of the event horizon, the boundary through which no light or matter can escape. Scientists have also seen the mesmerizing swirl of the black hole at the center of our own galaxy and observed giant electromagnetic jets shooting from the supermassive black hole at the heart of the galaxy Perseus A. Recently, they peered into the heart of a quasar, a superluminous galactic core powered by a massive black hole.

The EHT needs to be large because it relies on the ability to observe the universe continuously over eight- to 14-hour stretches from several angles, according to the Black Hole Partnerships for International Research and Education, a collaboration that develops the algorithms used by the telescope. These algorithms also rely on Earth's rotation to overlap observations, allowing researchers to combine images from numerous telescopes. Only then can they peer into some of the biggest, yet hardest-to-see phenomena in the universe.

The legacy of our ancient human relatives, "brain-eating-amoeba" infections, emerging viral threats, the promise and peril of genome editing, and much, much more — in 2024, Live Science covered a plethora of fascinating, and occasionally concerning, health studies. Research granted new insight into the human body's inner workings, the germs that can push our physiology off the rails, and the emerging technologies and drugs that could change medicine as we know it.

Here are some of my favorite stories from the past year. Keep up with us in 2025 to see how these diverse lines of research progress!

Bird flu

H5N1, a subtype of bird flu, reached the U.S. in late 2021, when it began inflecting wild birds, domestic poultry and the occasional mammal. This year, we learned for the first time that the virus can infect cows — and that it can jump from cows to people. At this point, there's been no evidence of H5N1 spreading from one person to another — an ability that could set the stage for a major outbreak, or even a pandemic. But Live Science has closely followed new discoveries about the virus: how it lingers in raw milk, is evolving to better infect mammals, could become deadlier if it mingles with seasonal flu, and is just one mutation away from being a "good match" for humans. We'll keep up with H5N1 in 2025, when mounting surveillance efforts by scientists should give a better sense of how big this problem could become.

Related: 9 of the most 'genetically isolated' human populations in the world

Our ancient ancestry

Modern humans mated with Neanderthals at several points in our history, and today, you can dust for genetic "fingerprints" left by our Neanderthal relatives. Some regions of the human genome contain up to 80% Neanderthal genes, while others, such as the X and Y chromosomes, are nearly or completely Neanderthal-free. These genes influence our face shape, skin color, circadian clock and immune function — and, in some contexts, they may do more harm than good. In an intriguing feature story, staff writer Emily Cooke explores the ways our Neanderthal genes may affect our health and biology today.

Battling brain-eaters

"Brain-eating" amoebas kill nearly everyone they infect, but new and emerging treatments could change that. A drug called miltefosine — originally designed to treat the parasitic disease leishmaniasis — has saved some patients' lives. And scientists are investigating other possible treatments, including antibiotics, mRNA vaccines and even a pigment derived from algae. Hopefully, someday, these rare infections won't be a nearly assured death sentence.

CRISPR

Scientists unveiled a new CRISPR system that reversibly "pauses" genes, rather than permanently disabling them. CRISPR innovator Virginijus Šikšnys spoke with Live Science about the future of the field and how the technology could render incurable diseases curable. On the flip side, doctor and science communicator Dr. Neal Baer discussed how, in the wrong hands and without adequate regulation, CRISPR could also become an instrument of eugenics.

Honorable mentions

To stop antibiotics from becoming obsolete, researchers are seeking ways to reverse antibiotic resistance. Researchers discovered a new hormone that helps build strong bones, particularly after pregnancy. A study highlighted how a quirk in forensic DNA analysis could end up linking the wrong people to crimes. Psychedelics are being tested as therapies, but major trial issues are hindering their approval. The male hormone cycle is linked to brain shrinkage over the course of the day, while pregnancy is tied to brain shrinkage across gestation. Several studies found that human aging might happen in distinct waves — but we're not sure why.

Nature has an unparalleled ability to inspire, awe and humble us, and 2024 was no exception.

From haunting underwater whale graves to jaw-dropping images of predators catching their prey, here are the most stunning nature photos captured in 2024.

Every autumn, millions of monarch butterflies (Danaus plexippus) migrate nearly 3,000 miles (4,800 kilometers) from North America to southwestern Mexico to hibernate over the winter, according to the National Museum of Scotland.

Photographer Jaime Rojo snapped this image of the butterflies clustered over fir trees in the El Rosario sanctuary, a UNESCO World Heritage site that's home to many overwintering monarch butterflies. The photo was awarded the grand prize at the 11th annual Big Picture: Natural World Photography competition.

In the tropical wetlands of the Pantanal, in South America, photographer Ian Ford captured the moment a jaguar (Panthera onca) delivered a skull-crushing bite to a yacaré caiman (Caiman yacare).

The image, titled "Deadly bite," was among the highly commended images in the 2024 Wildlife Photographer of the Year competition, developed and produced by the Natural History Museum in London.

Related: See a jaguar shattering a crocodilian's skull and a 'David Bowie' spider in this sneak peak of the 2024 Wildlife Photographer of the Year

Photographer Shane Gross was awarded first place in the Ocean Portfolio category in the Ocean Photographer of the Year 2024 competition.

In this photo, a litter of wide-eyed baby plainfin midshipman fish (Porichthys notatus) rest above golden yolk sacs that are still attached to their bodies.

Photographer Kathleen Borshanian captured this image of an Arctic fox pup basking in the sun on the edge of a cliff on an island in the Bering Sea.

The Pribilof Islands Arctic fox (Vulpes lagopus pribilofensis) is endemic to the Pribilof Islands — four volcanic islands off the coast of Alaska. The fox in this image lurks near an entrance to one of many tunnels found all over the island. These tunnels form an underground maze and provide refuge for these pups, according to the image caption.

The photo was among the finalists in the Terrestrial Wildlife category in the 2024 Big Picture: Natural World Photography competition.

Below the towering trees of a pine plantation, photographer Toby Schrapel captured a photo of a biofluorescent southern brown tree frog (Litoria ewingii) perched atop a glowing bioluminescent ghost mushroom (Omphalotus nidiformis).

This photo was awarded first place in the People's Choice category in the 2024 Beaker Street Science Photography Prize competition in Australia.

Related: 'Absolutely magical': Rare glowing duo of tree frog and parasitic ghost fungus captured in otherworldly photo

This photograph shows a forensic expert meticulously lifting the fingerprints from the tusk of an African elephant (Loxodonta) at Heathrow Airport in the U.K.

Photographer Britta Jaschinski sheds light on the illegal ivory trade that drives the poaching of elephants for their prized tusks. Fingerprints on ivory typically fade within a few hours, but forensic experts have pioneered a groundbreaking technique that enables investigators to lift fingerprints from tusks more than a month later.

This image was a finalist in the Human and Nature category in the 2024 Big Picture: Natural World Photography competition.

In this photo, titled "The Swarm of Life," a school of western toad tadpoles (Anaxyrus boreas) swims beneath a dense carpet of lily pads floating in a Canadian lake.

This species is found in a variety of habitats, from southeastern coastal Alaska and British Columbia, Canada, to northern Baja California, Mexico. Female western toads produce over 12,000 eggs in one clutch, but only 1% typically make it to adulthood.

Photographer Shane Gross captured this photo while snorkeling in a mountain lake on Vancouver Island. The photo was the grand title winner in the 2024 Wildlife Photographer of the Year competition.

Sockeye salmon (Oncorhynchus nerka) swerve around a swimming brown bear (Ursus arctos) at Katmai National Park in Alaska as the fish return from their annual migration.

In early June, up to 40 million adult sockeye salmon return to Bristol Bay from the open ocean, where they have spent around three years. They swim up the lakes and streams to the spot where they were birthed to lay their own eggs and soon after die.

The photographer, Barrett Hedges, was a finalist in the People's Choice category in the 2024 Big Picture: Natural World Photography competition.

Under a microscope, an incredibly detailed photo reveals the beady eyes of a green crab spider (Diaea dorsata).

Crab spiders are known for their distinct colors, which allow the critters to blend in with the foliage in woodlands across Europe.

Photographer Paweł Błachowicz was awarded 13th place for this photo in the Nikon Small World 2024 Photomicroscopy competition.

Whale graveyard

Beneath the coastal waters of East Greenland, a photographer captured the skeletal remains of minke whales resting in an underwater grave.

Photographer Alex Dawson took the image close to the Tasiilaq settlement, a small village that takes part in an annual hunt of the common minke whale (Balaenoptera acutorostrata). The whales are stripped of their meat and dragged back into the sea. Over time, their carcasses are picked clean by all kinds of marine animals.

The image, titled "Whale bones," was awarded the overall prize in the Underwater Photographer of the Year 2024 competition.

Related: Eerie photograph captures whales hunted off Greenland lying in their watery grave

Photographer Tracey Lund snapped this photo of a pair of swimming northern gannets while on vacation in Scotland's Shetland islands.

With a wingspan of 5.9 feet (1.8 meters), northern Gannets (Morus bassanus) are the largest seabirds in the U.K. They dive from heights of 98 feet (30 m) into the ocean to hunt for fish.

"Thousands of gannets were in the sky above us and then started to dive into the sea after local fish," Lund said in the photo caption. "An unbelievable spectacle to witness, let alone photograph."

The image won the grand prize in the 2024 World Nature Photography Awards and also took the gold award in the Behavior category.

In this photo, taken in the Axel Lab at Columbia University, a clutch of eggs reveals the early development of the rare Caribbean two-spot octopus (Octopus hummelincki).

This entire cluster measures around 0.4 inch (1 centimeter) in diameter, according to an Instagram post from one of the photographers who captured the image. Within each egg, there are two dark eyes; a small, white yolk sac; and brown chromatophores, pigment-containing cells that allow octopuses to change their appearance.

Photographers Thomas Barlow and Connor Gibbons were awarded fifth place in the Nikon Small World 2024 Photomicrography Competition.

A mahi-mahi (Coryphaena hippurus) makes a successful catch during a feeding frenzy in this photo taken off the coast of Baja California.

"Watching them hunt was mesmerising — their speed and precision were unreal," photographer Manuel Castellanos Raboso told Oceanographic magazine. "I wanted to capture the moment one broke through the ball with its catch. It took over 16 hours in the water, finding the right light and angle, but I finally got it."

The image was awarded first place in the Wildlife Photographer of the Year category in the Ocean Photographer of the Year 2024 competition.

Related: Ocean Photographer of the Year 2024: See stunning photos of hungry whale, surfing seagull, freaky fish babies, land-loving eel and adorable toxic octopus

This image of a potbelly seahorse hidden behind a green coral in the murky waters off Sydney landed photographer Talia Greis first place in the Macro category in the Underwater Photographer of the Year 2024 competition.

The potbelly seahorse (Hippocampus bleekeri) is one of the largest seahorse species. They are found along the coasts of Australia and New Zealand. They can reach 11.8 inches (30 cm) in length, and as the name suggests, adult potbelly seahorses have very large bellies.

This colorful image shows an emperor shrimp (Periclimenes imperator) riding on the head of a nudibranch (Hypselodoris apolegma) that is sitting on its eggs.

Nudibranchs, also known as sea slugs, lay their eggs in the shape of a ribbon or tight spiral.

Photographer Enrico Somogyi snapped this image off the northeast coast of Bali and was awarded first place in the Compact category in the Underwater Photographer of the Year 2024 competition.

It's often claimed that many of today's Christmas traditions derive from the pre-Christian observances of pagan cults suppressed by Roman authorities. The story goes that, after Christianity became the state religion of the Roman Empire in the fourth century, zealous imperial authorities sought to impose the new faith on the empire's millions of inhabitants by co-opting their established pagan traditions — including the date when a new festival was celebrated.

But it seems that the pagan influence on some Christmas traditions may have been overstated. Here is a look at seven Christmas traditions and their origins.

12 Days of Christmas

In Christianity, the "Twelve days of Christmas" — now mostly famous as a carol — referred to the time it took the "magi" (also known as the "wise men" or "magic kings") to arrive at the birthplace of Jesus. At least three magi (some sects say there were 12), who were supposedly astrologers from distant lands, followed a new star to Bethlehem. They were the first to see the baby after his family and some local shepherds, and so the magi's arrival represented the manifestation of Christ to people who were not Jewish — an important religious allegory. As a result, "Three Kings Day" or "Epiphany" at the end of the 12 days was once a major festival throughout Christian Europe, but today it is big only in Spain.

Historian Ronald Hutton, in his book "The Stations of the Sun: A History of the Ritual Year in Britain" (Oxford University Press, 1996), cites evidence that the 12 days originated in pre-Christian Celtic and Germanic traditions. Hutton argues that several practices carried out during the "Twelve Days of Christmas" in England's Middle Ages — such as the custom of wassailing, which was mostly walking about drinking "goodwill to all" but also blessing crops and fruit trees — originated in pagan practices.

Christmas trees

Some of the loudest claims of pagan origins surround the tradition of evergreen Christmas trees, a practice even the White House observes. But while pagans considered evergreen trees magical, many historians agree that the modern practice has Christian German origins. It seems Christmas trees may have begun with the medieval Christian tradition of decorating "Paradise trees" — representations of the Tree of Life, as described in the Bible's Book of Genesis. People celebrated "Adam and Eve Day" on Christmas Eve by performing their biblical story as a "Paradise Play," and so the decorative "Paradise trees" from the plays became a seasonal tradition in Germany. Historian and archaeologist Ken Dark of King's College London told Live Science that the tradition was cemented in 1848, when Britain's royal family published a Christmas engraving that showed Queen Victoria and her husband Prince Albert (a German) with their family and decorated tree.

Yule

The terms "Yule" and "Yuletide" now refer to Christmas, but it wasn't always so: There is strong evidence that Yule was originally an ancient Germanic and Norse festival season marking the winter solstice — the longest night — and the eventual return of the sun. Hutton suggests the Yule season, or Yuletide, originally covered a period of about 24 days during midwinter and began a few days before Dec. 25. The pagan Yuletide was associated with gift-giving and feasting — practices reflected in Christmas traditions — but most famously with bonfires and the Yule log. Over centuries, the Yule log has transformed into the tradition of a crackling wood fire at Christmas; American versions include a televised burning log and now rocket engines.

Mistletoe

The Christmas tradition of kissing under a sprig of mistletoe seems to come from 18th-century England: A 1719 report about superstitions surrounding the plant doesn't mention the practice, but a poem from 1784 does. Mistletoe is an evergreen that was used for Christmas decorations because of its bright green leaves and white berries. Historians aren't sure why the idea of kissing arose, but it may be that an earlier pagan superstition became confused with the Christian tradition: Mistletoe was supposedly sacred to the Celtic druids, and it appears in a Norse legend. Mistletoe also featured in ancient Greek and Roman marriage ceremonies, where it was thought to ensure fertility.

Santa and Odin

It's been suggested that the seasonal character of "Santa Claus" or "Father Christmas" was influenced by the Norse god Odin. Odin was the head of the Norse pantheon and the god of death and magic; whereas Santa Claus originated with the Christian figure of Saint Nicholas, a fourth-century bishop in Anatolia, now Turkey. Both Odin and Saint Nicholas were usually depicted as old men with big beards, which might be considered proof of the idea; but according to the author Phyllis Siefker in "Santa Claus, Last of the Wild Men: The Origins and Evolution of Saint Nicholas, Spanning 50,000 Years" (McFarland, 1997) Odin was also associated with gift-giving during Yuletide and magical flight on his eight-legged horse Sleipnir, which became Santa's team of flying reindeer. Dark said few historians take this idea seriously.

December 25th

The traditional date for the celebration of Christmas in the West is the 25th day of December, which in the Northern Hemisphere is close to the shortest day of the year, or winter solstice around Dec. 21. Several pre-Christian religions marked the shortest day with ceremonies, including the Imperial Roman cult of Sol Invictus (Latin for "unconquered sun"); and some researchers have proposed that the date of Christmas was deliberately chosen to supersede these pagan celebrations. But Dark notes that the suppression of earlier festivities, such as the Saturnalia celebrated in pagan Rome in mid-December, does not necessarily mean that the Christmas date was intended to supplant them directly. Instead, he said, it may be that Christian authorities only wanted to fill a gap in their ceremonial calendar.

Turkey for Christmas dinner

Christmas dinner often features roast turkey in America, where the birds are plentiful; and this is sometimes seen as a modern version of a pagan tradition of seasonal feasting. But there is no historical evidence that this was the case, and feasting is a common way of celebrating holidays. The original "turkeys" were guinea fowl native to Africa, and the name was applied to the similar-looking American birds, which were unknown in Europe before the discovery of the New World. But guinea fowl were a hard-to-get luxury, and so most people settled for lesser birds like ducks or chickens. In 1843's "A Christmas Carol" by Charles Dickens, for example, the Cratchit family plans to eat a goose. Dark notes that the idea of feasting on stuffed fowl at Christmas is not universal, and that many English families once celebrated instead with roast beef dinners and Christmas hams.

People have been fascinated by Neanderthals ever since we discovered their bones in a German cave in the mid-19th century. Their stocky bodies and huge heads give us a fun-house-mirror glimpse into the evolutionary road we might have traveled. Even though DNA research has shown that all modern-day human populations have a little Neanderthal in them, we still view our Neanderthal cousins as the black sheep lineage of the Homo genus.

Here's a look at 10 things we've learned about our closest known relatives — and, by extension, ourselves — this year.

Related: Lucy's last day: What the iconic fossil reveals about our ancient ancestor's last hours

1. Neanderthals had a keen sense of fashion.

Neanderthals lived in Europe, so they had to protect their bodies from frostbite and other cold-related problems. Although no frozen caveman clothing has ever been discovered, archaeologists think Neanderthals wore clothing to help maintain their core body temperature.

Circumstantial evidence of Neanderthal clothing includes a stone tool with residue from hide scraping, pointed bone awls used to punch holes in hides, and a twisted bit of cord, possibly from shoes or fabric.

The kind of clothing Neanderthals wore is still being debated, but it was likely more elaborate than a loincloth. If Neanderthals were wearing parkas, pants and boots, they were probably the first fashionistas, researchers told Live Science.

2. Neanderthals cared for their comrades with disabilities.

A fragment of a Neanderthal child's ear bone suggests she had Down syndrome and that she was cared for by her community. In a study published in June in the journal Science Advances, researchers identified a 6-year-old Neanderthal child nicknamed "Tina" in a cave in Spain. Tina's ear bone, which dated to between 273,000 and 146,000 years ago, has a shape associated with Down syndrome, as well as other abnormalities.

Although no genetic work has conclusively shown that Tina had Down syndrome, she nevertheless would have required care from her community to survive, according to the researchers, since her ear bone also suggested she had major hearing loss and vertigo. The finding suggests that other Neanderthals were helping her and her mother out of a sense of altruism.

3. Neanderthals created an early "glue factory."

As far back as 65,000 years ago, Neanderthals on the Iberian Peninsula were skilled engineers who made sticky tar in a precisely controlled environment. In the December issue of the journal Quaternary Science Reviews, researchers detailed their discovery of a hearth in a cave floor in Gibraltar. The hearth was full of charcoal and plant resin and was likely heated to 300 degrees Fahrenheit (150 degrees Celsius) to produce the gooey glue, which would have been used to fashion weapons such as spears.

The findings show Neanderthals were both very intelligent and able to collaborate to produce complex tools.

4. Modern humans and Neanderthals buried their dead differently.

Putting a dead body in a hole and covering it up is a burial practice exclusive to humans and Neanderthals. But Neanderthals buried their dead differently than Homo sapiens, according to research published this summer in the journal L'Anthropologie.

By looking at burials in Western Asia over a span of 85,000 years — when modern humans and Neanderthals overlapped — researchers noticed both similarities and differences. Everyone buried their dead without regard to their sex or age, and both modern humans and Neanderthals put items in their graves. But while Neanderthals buried their dead in a variety of positions in caves, early H. sapiens buried theirs in the fetal position outside caves.

Neanderthals and H. sapiens started burying their dead during the same time period — about 90,000 to 120,000 years ago — perhaps to mark their territory or lay claim to certain resources in a landscape teeming with hominins.

Related: From 'Lucy' to the 'Hobbits': The most famous fossils of human relatives

5. They looked a lot like us.

Numerous burials found in Shanidar Cave in Iraq provide some of the earliest evidence of purposeful interment of the dead. The skull of a woman known as Shanidar Z was pieced together from hundreds of fragments, and her face was reconstructed to provide a picture of one of our extinct relatives.

Neanderthal skulls look different from those of modern humans; they have huge brow ridges, prominent noses and no chin. But when muscles and skin are put back on the bone, even virtually, the similarities between Neanderthals and humans are apparent, and their long history of interbreeding is not surprising.

6. The last Neanderthals were isolated.

DNA sequencing of a Neanderthal nicknamed "Thorin" revealed that some groups may have been isolated for thousands of years before going extinct. Discovered in France's Rhône Valley, Thorin was dated to between 52,000 and 42,000 years ago. His DNA suggested that his lineage was quite inbred, even though other Neanderthal groups lived nearby.

"How can we imagine populations that lived for 50 millennia in isolation while they are only two weeks' walk from each other?" said Ludovic Slimak, a researcher at the Center for Anthropobiology and Genomics of Toulouse in France and lead author of the research. "Everything must be rewritten about the greatest extinction in humanity."

7. Male Neanderthal DNA seems to have vanished without a trace.

Although plenty of genes are shared between modern humans and Neanderthals, the H. sapiens genome does not have any Neanderthal Y chromosome DNA, which raises the question of how and why this genetic material vanished.

One intriguing possibility is that mating simply didn't work between Neanderthal males and H. sapiens women. Even though the two groups interbred several times over thousands of years, if a human mother was pregnant with a male Neanderthal baby, her immune system may have attacked the male fetus with unknown Y chromosome genes during pregnancy, resulting in a miscarriage. Eventually, if fewer male Neanderthal hybrid babies were born, the Y chromosome genes would disappear.

But it is not yet certain why the Neanderthal Y chromosome is no longer in our evolutionary gene pool. Because it is passed down only from father to son, it may have simply been lost over the generations.

8. Neanderthals were probably absorbed into modern-human groups.

Two key studies published recently showed that, although Neanderthals disappeared as a group, many of their genes did not.

By looking at more than 300 human genomes from the past 45,000 years, researchers estimated that most of the Neanderthal DNA that persists in us is from almost 7,000 years of interbreeding that began around 47,000 years ago.

Conversely, research published in July in the journal Science estimated that the Neanderthal genome may have been between 2.5% and 3.7% human, indicating that both human and Neanderthal populations had a long history of exchanging mates. The genetic analysis also revealed that the Neanderthal population size was quite small. The finding suggests that, rather than undergoing a dramatic extinction, the Neanderthals were simply absorbed into larger human groups.

Related: Ancient human ancestor Lucy was not alone — she lived alongside at least 4 other proto-human species, emerging research suggests

9. Neanderthal DNA affects our health.

Ongoing DNA research also revealed that our health is affected by Neanderthal genes, for better or for worse.

Humans inherited Neanderthal genes for certain pregnancy hormones, which are associated with increased fertility and a lower risk of miscarriage. But other gene variants from our Neanderthal cousins make us more susceptible to allergies and Type 2 diabetes, more sensitive to pain and sunlight, and more likely to be at risk for nicotine addiction, severe COVID-19, autoimmune conditions and depression.

10. Humans probably did not kill off Neanderthals — at least, not directly.

We also learned that modern humans didn't purposely kill off the world's last Neanderthals. In addition to absorbing some of the Neanderthals through interbreeding and gene exchange, humans appear to have simply outcompeted Neanderthals by falling back on our vast social networks when times were tough and leaving our introverted cousins high and dry.

So who was the last Neanderthal? Although researchers still don't know for sure, current evidence points to southern Iberia as a potential location for Neanderthals' last stand around 37,000 years ago. After that time, Neanderthals as a distinct group ceased to exist, although they live on, in part, through the genes they shared with us.

Over the past 50,000 years, humans have populated nearly every corner of the globe — and due to geographic barriers, some of these populations then remained isolated for thousands or even tens of thousands of years.

Other populations have become cloistered thanks to insular cultural or religious practices. As a result, the genetic diversity of our species has declined over the past 50 millennia.

Genetic diversity in a given population can be reduced in what is known as a "founder event" — when a small group of people splits off from a larger population, which leads to a smaller gene pool in the isolated group. In a study of 460 populations around the world, roughly half showed evidence of a recent founder event, researchers concluded in 2022.

Here's a look at some of the most genetically isolated groups of modern humans — and how these isolated populations are helping researchers better understand humans' unique abilities and diseases that affect some groups more than others.

1. Anabaptists — Amish, Mennonites and Hutterites

These Christian groups originated in the 16th century, and many moved to America in the 17th century, settling in rural areas such as southeastern Pennsylvania. All of these populations have had significant founder effects and genetic bottlenecks over the past few centuries, and in 2011, a database was created to keep track of genetic disorders common to the Anabaptists.

For example, maple syrup urine disease, an inherited condition that involves problems processing the amino acids that make up proteins, is rare in the general population but affects 1 in 380 Old Order Mennonites. And the modern Hutterites descend from just 67 people, which has resulted in a higher than average rate of cystic fibrosis within the population.

2. Parsis

The Parsis are a community of Zoroastrians who migrated to India from Persia in the seventh century. Traditional Parsis disapprove of marriage outside of their religion, which may have led to the group's isolation.

Geneticists are particularly interested in the longevity of the Parsis, who have gene variants correlated with living well into their 90s, despite the higher-than-average rate of breast cancer in women. A 2021 study published in Meta Gene concluded that the Parsi practice of endogamy — marrying within their group — was likely the reason for these particular traits.

3. Sherpa

The Sherpa in the mountains of Nepal have remained genetically isolated for centuries, likely in part because of the forbidding landscape they inhabit. The group moved from Tibet between 400 and 600 years ago and are best known as highly skilled Mt. Everest guides. Although the Sherpa have plenty of neighbors, a 2017 study in the journal BMC Genomics showed that their genome has little evidence of gene flow from nearby Nepali groups.

Geneticists are particularly interested in the Sherpa's ability to thrive at high altitudes, which a 2014 study in the journal Nature Communications found to be linked to the groups' unique genetics that likely evolved within the last three millennia.

4. Papua New Guineans

When modern humans arrived in New Guinea roughly 50,000 years ago, they met and mixed with the Denisovans, a now-extinct group of human ancestors who originated in Asia. But after that initial meet-up, Papua New Guineans became genetically isolated for tens of millennia — even within the country itself.

A 2017 study published in the journal Science showed a sharp divide between the gene variants of people living in the highlands versus the lowlands. And a genome study published in the journal Nature Communications in 2024 showed that Papua New Guineans inherited unique gene variants from the Denisovans that may help people in the lowlands fight off infections and the people in the highlands live at high altitudes.

Related: Gene mutation helps Andean highlanders thrive at altitude, and 'living fossil' fish live deep underwater

5. Nunavik Inuit

The North American Arctic was the last region of the world to be settled by humans, beginning roughly 6,000 years ago. Inuit people arrived in Nunavik, the northernmost part of the Canadian province of Quebec, about seven or eight centuries ago. A 2019 study of 170 genomes of Nunavik Inuit people found that the Nunavik Inuit had little admixture with outside groups, leading to some unique gene variants.

In particular, their genomes seemed to reflect an increased ability to metabolize fat and protein, important for surviving a bitterly cold climate with few plant-sources of food. But the researchers also discovered the Nunavik Inuit had a much higher-than-normal genetic risk for brain aneurysms resulting from founder effect.

6. Antioqueños

A genetically isolated community in northwest Colombia, called the Antioqueños or Paisas, carries a rare genetic variant that puts people at increased risk of early-onset Alzheimer's disease (AD).

The province of Antioquia was founded by a small population of Spanish men and Indigenous women, and a 2006 study in the journal PNAS found that their descendants continued to pair up with Spanish men, but not with Indigenous women or men. Over time, this likely created a genetically isolated population, the study found. Many Antioqueños carry a rare genetic mutation that leads to cognitive impairment by age 45 and AD by age 50 — people typically develop the disease after age 65. But by studying this group, researchers hope to develop antibodies that could protect people against AD in the future.

7. Ashkenazi Jews

This Jewish diaspora group migrated from the Middle East and into Central and Eastern Europe in several waves, including one following the Crusades. A 2006 study in the American Journal of Human Genetics showed that around half of the 8 million Ashkenazi Jews living today can trace their maternal lineage to just four original groups. Later a 2022 study in the journal Cell revealed that this founder event happened at least seven centuries ago.

One potential issue with founder events is that inherited disorders can become more common in the population, because a small gene pool may "trap" gene variants. Tay-Sachs disease, a brain and spinal cord disorder that affects children, is rare in the general worldwide population but is more common in Ashkenazi Jews, with about 1 in 3,500 children in the population affected at birth. The condition also crops up in the Amish — another genetically isolated group.

8. Finns

Over the course of its history, Finland has had at least two major population bottlenecks, in which the population dwindled in number but then resurged. These bottlenecks, plus the relatively sparsely populated and geographically isolated nature of the country, led to an increase in the frequency of certain gene variants.

The Finns created a database, called Finnish Disease Heritage, that catalogues dozens of recessive genetic disorders commonly seen in ethnic Finns that can severely affect their health, including types of epilepsy and muscular dystrophy. On the other hand, the Finns' unique genetics make other conditions — such as cystic fibrosis and phenylketonuria — rare in people of ethnic Finnish heritage.

9. Tristan da Cunha

Tristan da Cunha, in the south Atlantic Ocean, is part of the most remote inhabited archipelago in the world. Today, it is a part of the British Overseas Territories and is home to only about 250 permanent residents. But when it was first settled in 1816, the population was somewhere between 15 and 28 people, making Tristan a textbook example of a founder effect.

A study published in the 1960s found that the Tristan population had a higher-than-expected number of people affected by retinitis pigmentosa, an inherited eye disease that causes vision loss, and a 2019 study revealed abnormally high frequencies of asthma within the population.

Like many children, I had a natural curiosity for the living world from a young age. My childhood was filled with bug-hunting, pond-dipping and watching David Attenborough documentaries. As a young adult, the books I read on biology and evolution became a bridge between my childhood curiosity and my adult obsession. I'm fortunate that my career allows me to indulge in my long-standing passion.

Having earned an undergraduate degree from the University of Edinburgh and a DPhil in evolutionary biology from the University of Oxford, I am now a professor of microbial ecology and evolution at the University of Bath in the U.K., where my lab uses an approach called experimental evolution, which allows the observation of evolution in real-time using microbes. Very broadly, we are interested in the patterns and processes that shape life’s resilience and innovations and study these by tracking the fate of mutations within a population, as determined by natural selection, within bacterial populations.

While I consider myself an evolutionary biologist, over time I began to appreciate microbes not just as tools for studying evolution but for their fascinating biology, for their essential role in the health of humans and the planet, and for the unassuming beauty they possess when observed closely. Both these threads — evolution and microbes — continue to be central to my research today.

Related: Best science books for kids and young adults

There are many excellent science books that offer a gateway into the fascinating fields of evolution and microbiology. Here are my top five reads that have, in some way, changed my personal or scientific perceptions of the world.

The first book I recommend is "Beautiful Bacteria: Encounters in the Microuniverse" by Tal Danino.

Danino’s research involves engineering glowing bacteria that form distinctive, rhythmic patterns of fluorescent proteins as they move across the plate. Recognising the beauty in his work, his book showcases visually stunning photographs of bacteria that blur the lines between art and science. I find myself equally amazed by and curious about the underlying processes that can create such beauty.

My own research also involves looking at bacteria that swim across the plate. My first experiment with bacteria involved counting green and white colonies on an agar plate — a dish filled with a jelly-like food source on which you can grow bacteria. The green ones excreted a protein that helped them scavenge the iron they needed to grow when iron was scarce (like in the human body), while the white ones had a mutation preventing this. I loved coming to the lab in the morning and seeing these different microbial hues, it gave the bacteria character somehow, and it made me appreciate that bacteria had an aesthetic appeal, as well a practical one. Danino's book reminds me of this, and to stop and wonder at the patterns as well as the process when I can.

Another book that looks at the tiny microbes I spend all day in the lab with is "I Contain Multitudes: The Microbes Within Us and a Grander View of Life" by Pulitzer Prize winner Ed Yong. I spend a lot of time trying to convince people that bacteria are fascinating and worth understanding, and in his New York Times bestseller, Yong masterfully uses rich, vivid descriptions to bring microscopic worlds to life. He explores hidden ecosystems that exist in and on every living thing and delves into the lives of the researchers studying them.

The impact of microbes cannot be underestimated: They have a profound impact on our environment and health and are responsible for driving the evolution of complex life. Our microbiomes, the bacteria that live in and on our bodies which at least equal and may exceed the number of human cells, are in constant flux, adapting to and interacting with our environments. Yong leaves us with the message that understanding and nurturing these microbial communities can benefit us all. This book underscores the importance of effective science communication and its power when done well.

Much of my work explores the origins of new genes with new functions. Andreas Wagner's book "Arrival of the Fittest: How Nature Innovates" shaped many of my early ideas when I was setting up my lab. Taking inspiration from Charles Darwin's seminal work on evolution, he seeks to understand not the survival but the arrival of the fittest. Where does the variation on which natural selection acts come from?

Wagner begins at life’s possible starting point — a deep-sea vent, where interacting chemical molecules changed into something we recognise as life. He challenges the notion that random mutations alone account for life’s diversity, highlighting the vastness of sequence space — the universal library of all proteins that have and could be created. For example, in a small protein with only 100 amino acids, the number of permutations to explore is greater than a 1 with 130 zeros trailing behind.

Wagner illustrates that only a fraction of this space needs exploration to find significant innovations, transforming our understanding of randomness in life's evolutionary journey.

Books for kids and about them

Away from the world of bacteria and evolution, another one of my passions is children's' literature. In 2022, I sat on the panel of the Royal Society’s Young People’s Book Prize, which promotes literacy in young people and inspires them to read about science. "Microbe Wars" was my favorite among those shortlisted.

Arbuthnott and Madriz deliver a captivating introduction to the microscopic world in an engaging and accessible manner for young readers. They use humor and storytelling to convey scientific concepts and highlight the people and history behind microbiological discoveries. It fills me with joy that my children can learn how we owe vaccines to milkmaids who were seemingly protected from smallpox, or how epidemics like the Black Death have shaped human history. Best of all, this knowledge sparks their curiosity, leading to lively discussions about the exciting discoveries we're making in my lab.

And finally, while not related to my research, the book "Bumpology: The Myth-Busting Pregnancy Book for Curious Parents-To-Be" has been important as my role as both a scientist and a parent. Balancing parenthood and a career is a tough challenge — I’ve spoken openly about the importance of ensuring that motherhood doesn't feel incompatible with a scientific career, and I strive to support parents navigating this difficult period.

As a scientist, I thrive on data, relying on evidence and careful analysis rather than assumptions. Pregnancy and parenting, however, are often surrounded by anecdotes and old wives' tales. Don’t get me wrong, I too have tried to exactly replicate a successful sleep routine after a rare good night's sleep. But science isn't about assumptions — it's about data.

Geddes exploits the skills developed in her previous role as a journalist for New Scientist, and leverages the latest research of the time to bust myths and provide evidence-based answers to common questions about pregnancy and early infancy. This book is packed with scientifically-backed advice and fascinating insights you might never have thought to ask about.

Evolution quiz

Reading list

One night about 60 years ago, physicist Enrico Fermi looked up into the sky and asked, "Where is everybody?"

He was talking about aliens.

Today, scientists know that there are millions, perhaps billions of planets in the universe that could sustain life. So, in the long history of everything, why hasn't any of this life made it far enough into space to shake hands (or claws … or tentacles) with humans? It could be that the universe is just too big to traverse.

It could be that the aliens are deliberately ignoring us. It could even be that every growing civilization is irrevocably doomed to destroy itself (something to look forward to, fellow Earthlings).

Or, it could be something much, much weirder. Like what, you ask? Here are 12 unusual answers that scientists have proposed for the Fermi paradox.

Related: 'It's hard not to believe he saw something': Historian Greg Eghigian on how UFOs took over the world

We're looking in the wrong universe

Maybe we haven't found aliens because our universe isn't particularly conducive to life. Maybe Earth is an anomaly — a lucky blue dot adrift in a vast ocean of darkness and dead worlds. Maybe we'd have better luck looking for life in the next universe over.

That last idea is the premise of a 2024 study that assumes our cosmos is just one possible universe within an endless "multiverse" of realities, each one slightly different from the rest. To test whether our universe has the optimal conditions for life to emerge, the researchers compared star formation rates here to star formation rates in a host of hypothetical, parallel universes with different concentrations of matter and energy.

The main factor the team considered was a universe's density of dark energy — a mysterious force that drives the constant, accelerating expansion of the cosmos. A universe with too much dark energy would expand too quickly, scattering star-forming material and stunting the growth of large-scale structures like galaxy clusters. But in a universe with too little dark energy, gravity might become overwhelming, causing large structures to collapse before habitable planets had the chance to form.

The team's models revealed that the optimal density of dark energy within a universe would enable up to 27% of ordinary matter to turn into stars. But in our universe, only an estimated 23% of matter turns into stars — meaning there are fewer stars here than there could be and, as a result, fewer places for alien life to emerge. Better luck in the next universe!

Aliens don't live on planets

Every alien species needs a habitable planet to live on, right? Surprisingly, a 2024 study argues that may not always be the case.

In a paper accepted for publication in the journal Astrobiology, researchers proposed a scenario in which an alien colony could survive by floating freely in space, no planet required. It may sound wild, but it's not without real-world precedent; humans, for example, can live for hundreds of days without a planet while residing on the International Space Station (albeit with constant deliveries of crucial resources from their planet), and hardy tardigrades can survive the vacuum of space.

A theoretical planet-free alien colony would have to overcome many challenges, including a lack of resources, exposure to cosmic radiation and the vacuum of space, and access to enough sunlight. With this in mind, the researchers paint the picture of a species that could survive these trials: a free-floating colony of organisms measuring up to 330 feet (100 meters) across, encased in a thin, hard, transparent shell that could maintain a livable temperature and pressure through the greenhouse effect.

Finding such a species is a long shot, but it's not impossible. A free-floating alien colony could also explain why no intelligent aliens are answering our calls: They don't have a landline to use.

The aliens are hiding in underground oceans

If humans hope to converse with ET, we'll need to have a few icebreakers handy. No, seriously — alien life is probably trapped in secret oceans buried deep inside frozen planets.

Subsurface oceans of liquid water slosh beneath multiple moons in our solar system and may be common throughout the Milky Way, astronomers say. NASA physicist Alan Stern thinks clandestine water worlds like these could provide a perfect stage for evolving life, even if inhospitable surface conditions plague those plants. "Impacts and solar flares, and nearby supernovae, and what orbit you're in, and whether you have a magnetosphere, and whether there's a poisonous atmosphere — none of those things matter" for life that's underground, Stern told Space.com.

That's great for the aliens, but it also means we'll never be able to detect them just by glancing at their planets with a telescope. Can we expect them to contact us? Heck, Stern said — these critters live so deep, we can't even expect them to know that there's a sky over their heads.

Fortunately, NASA's Europa Clipper spacecraft is on the way to one such moon to look for evidence of life up-close. The Clipper will arrive at Jupiter's frozen moon Europa in 2030.

The aliens are imprisoned on "super-Earths"

No, "super-Earth" is not Captain Planet's dorky cousin. In astronomy, the term refers to a type of planet with a mass up to 10 times greater than Earth's. Star surveys have turned up oodles of these worlds that could have the right conditions for liquid water. This means alien life could conceivably be evolving on super-Earths all over the universe.

Unfortunately, we'll probably never meet these aliens. According to a study published in 2018, a planet with 10 times Earth's mass would also have an escape velocity 2.4 times greater than Earth's — and overcoming that pull could make rocket launches and space travel near impossible.

"On more-massive planets, spaceflight would be exponentially more expensive," study author Michael Hippke, a researcher affiliated with the Sonneberg Observatory in Germany, previously told Live Science. "Instead, [those aliens] would be to some extent arrested on their home planet."

We're looking in the wrong places (because all aliens are robots)

Humans invented the radio around 1900, built the first computer in 1945 and are now in the business of mass-producing handheld devices capable of making billions of calculations per second. Full-blown artificial intelligence may be right around the corner, and futurist Seth Shostak said that's reason enough to reframe our search for intelligent aliens. Simply put, we should be looking for machines, not little green men.

"Any [alien] society that invents radio, so we can hear them, within a few centuries, they've invented their successors," Shostak said at the Dent:Space conference in San Francisco in 2016. "And I think that's important, because the successors are machines."

A truly advanced alien society may be completely populated by super-intelligent robots, Shostak said, and that should inform our search for aliens. Instead of focusing all our resources on finding other habitable planets, perhaps we should also look to places that would be more attractive to machines — say, places with lots of energy, like the centers of galaxies. "We're looking for analogues of ourselves," Shostak said, "but I don't know that that's the majority of the intelligence in the universe."

We've already found aliens (but are too distracted to realize it)

Thanks to pop culture, the word "alien" probably makes you envision a spooky humanoid with a big, bald head. That's fine for Hollywood — but these preconceived images of E.T. could sabotage our search for alien life, a team of psychologists from Spain wrote earlier this year.

In a small study, the researchers asked 137 people to look at pictures of other planets and scan the images for signs of alien structures. Hidden among several of these images was a tiny man in a gorilla suit. As the participants hunted for what they imagined alien life to look like, only about 30% noticed the gorilla man.

In reality, aliens probably won't look anything like apes; they may not even be detectable by light and sound waves, the researchers wrote. So, what does this study show us? Basically, our own imagination and attention span limit our search for extraterrestrialsy. If we don't learn to broaden our frames of reference, we could miss the gorilla staring us in the face.

Humans will kill all the aliens (or already have)

The closer we get to finding aliens, the closer we get to destroying them. That's one likely eventuality, anyway, said theoretical physicist Alexander Berezin.

Here's his thinking: Any civilization capable of exploring beyond its own solar system must be on a path of unrestricted growth and expansion. And as we know on Earth, that expansion often comes at the expense of smaller, in-the-way organisms. Berezin said this me-first mentality probably wouldn't end when alien life is finally encountered — assuming we even notice it.

"What if the first life that reaches interstellar-travel capability necessarily eradicates all competition to fuel its own expansion?" Berezin wrote in a paper posted in 2018 to the preprint journal arXiv.org. "I am not suggesting that a highly developed civilization would consciously wipe out other life-forms. Most likely, they simply won't notice, the same way a construction crew demolishes an anthill to build real estate because they lack incentive to protect it." (Whether humans are the ants or the bulldozers in this scenario remains to be seen.)

The aliens triggered climate change (and died)

When a population burns through resources faster than its planet can provide them, catastrophe looms. We know this well enough from the ongoing climate-change crisis here on Earth. So, isn't it possible that an advanced, energy-guzzling alien society might run into the same issues?

According to astrophysicist Adam Frank, it's not only possible but extremely likely. Earlier this year, Frank ran a series of mathematical models to simulate how a hypothetical alien civilization might rise and fall as it increasingly converted its planet's resources into energy. The bad news is that in three out of four scenarios, the society crumbled and most of the population died. Only when the society caught the problem early and immediately switched to sustainable energy did the civilization manage to survive. That means that, if aliens do exist, the odds are pretty high they'll destroy themselves before we ever meet them.

"Across cosmic space and time, you're going to have winners — who managed to see what was going on and figure out a path through it — and losers, who just couldn't get their act together, and their civilization fell by the wayside," Frank said. "The question is, which category do we want to be in?"

Aliens used clean energy, but still triggered climate change (and died)

A sufficiently advanced alien species will inevitably heat up its planet as its society and its energy needs grow. This could trigger runaway climate change, as humans are doing on Earth, and may doom those aliens to an early extinction. But what if the fast-growing alien society made an early switch to eco-friendly, renewable energy? Could that spare them, allowing the aliens to grow, thrive and expand throughout the cosmos without consequence?

Sorry, but no, according to a bleak theoretical study published to the preprint database arXiv in September 2024. The study found that an exponentially growing alien species using 100% renewable energy would still heat up their planet with waste heat, which is inevitably produced from any energy expenditure according to the second law of thermodynamics. This waste heat would continue to build up as long as the society's energy demands grew, eventually triggering disastrous climate change within 1,000 years of that society's industrial revolution.

If true, this means that an energy-guzzling alien race would likely never survive long enough to venture deep into the cosmos and set up shop on nearby planets. It's not only a sad outlook for aliens but an urgent wake-up call for Earth.

The aliens couldn't evolve fast enough (and died)

File another excuse under "the aliens are dead already" category. The universe may be teeming with hospitable planets, but there's no guarantee they'll stay that way long enough for life to evolve. According to a 2016 study from Australia National University, wet, rocky planets like Earth very unstable when they start their careers; if any alien life hopes to evolve and thrive on such a world, it has a very limited window (a few hundred million years) to get the ball rolling.

"Between the early heat pulses, freezing, volatile content variation and runaway [greenhouse gases], maintaining life on an initially wet, rocky planet in the habitable zone may be like trying to ride a wild bull — most life falls off," the study authors wrote. "Life may be rare in the universe not because it is difficult to get started, but because habitable environments are difficult to maintain during the first billion years.

Dark energy is splitting us apart

As we've already established, the universe is expanding. Slowly but surely, galaxies are moving farther apart, with distant stars appearing dimmer to us, all thanks to the pull of the mysterious, invisible substance that scientist call dark energy. Scientists speculate that within a few trillion years, dark energy will stretch the universe so much that Earthlings will no longer be able to see the light of any galaxies beyond our closest cosmic neighbors. That's a scary thought: If we don't explore as much of the universe as possible before then, such investigations may be lost to us forever.

"The stars become not only unobservable, but entirely inaccessible," Dan Hooper, an astrophysicist at the Fermi National Accelerator Laboratory in Illinois, wrote in a study earlier this year. That means we're on a serious deadline to find and meet any aliens out there — and to keep a step ahead of dark energy, we'll have to expand our civilization into as many galaxies as we can before they all drift away.

Of course, fueling that kind of growth won't be easy, Hooper said. It might involve rearranging the stars.

Twist ending: We ARE the aliens

If you left your house today, you saw an alien. The woman delivering mail? Alien. Your next-door neighbor? Nosy alien. Your parents and siblings? Aliens, aliens, aliens.

At least, that's one implication of the fringe astrobiology theory called the "panspermia hypothesis." In a nutshell, the hypothesis says that much of the life we see on Earth today didn't originate here but was "seeded" here millions of years ago by meteors carrying bacteria from other worlds.

Proponents of this theory have variously suggested that octopi, tardigrades and humans were seeded here from other parts of the galaxy — but unfortunately, there's no real evidence to back up any of that. One big counterargument: If bacteria carrying human DNA evolved on another nearby planet, why haven't we found traces of humanity anywhere besides Earth? Even if this hypothesis turns out to be plausible, it still doesn't help us answer Fermi's nagging question … Where is everybody?

Editor's note: This article was originally published in July, 2018. It was updated on Dec. 2, 2024 with new studies and information.

Editor's note: This is part of a special package written for the 50th anniversary of the discovery of a 3.2 million-year-old A. afarensis fossil (AL 288-1), nicknamed "Lucy."

Our ancestor "Lucy," a young adult Australopithecus afarensis, became world-famous half a century ago after Donald Johanson and colleagues discovered her remarkably complete skeleton in Ethiopia. Today, Lucy is an important touchstone in human evolution because she lived 3.2 million years ago, evolutionarily halfway between our ape ancestors and us.

But Lucy is just one of many famous hominin fossils. From the "Taung Child" to "the Hobbit," here are some of the most iconic fossils that have transformed what we know about human evolution and our tangled family tree.

Related: Our mixed-up human family: 8 human relatives that went extinct (and 1 that didn't)

Australopithecines

The very first australopithecine to be recognized as a bipedal hominin was the Taung Child, discovered by Raymond Dart in South Africa in 1924. He named the fossil Australopithecus africanus, which means "southern ape from Africa." However, it took nearly 20 years for the scientific community to accept the find, in part because the "missing link" between apes and humans was expected to be found in Asia or Europe, not in Africa. Now, the Taung Child is heralded as one of the most important fossils of the 20th century, as its skeleton helped to prove that bipedalism evolved before a large brain did.

Another complete skull from an adult A. africanus was nicknamed Mrs. Ples after its original genus, Plesianthropus ("near-human"). Mrs. Ples was discovered in 1947, when paleontologist Robert Broom accidentally blasted her skull apart while using dynamite to excavate in the Cradle of Humankind in South Africa. In spite of its inauspicious discovery, after the skull was reassembled, Mrs. Ples became the most complete australopithecine skull ever found, dating back 2.35 million years.

In 1959, an extremely robust australopithecine was discovered by Mary Leakey at Olduvai Gorge in Tanzania. Leakey originally named the skull Zinjanthropus boisei — "Zinj" is an old name for East Africa — and affectionately called him "Dear Boy." But his massive jaws, as well as teeth four times the size of humans', led the press to nickname him "Nutcracker Man."

This discovery proved that there were two kinds of australopithecines — one very robust and one more slender — roaming Africa 2.5 million to 1 million years ago. When this new fossil was reported at a conference, Dart reportedly joked, "What would have happened if Mrs. Ples had met Dear Boy one dark night?"

The Homo genus

Although Lucy is a comprehensive specimen, the most complete individual ever found is that of Nariokotome Boy, a Homo erectus who lived about 1.5 million years ago. Also called Turkana Boy, this youngster, who was 11 or 12 years old when he died, was found in 1984 in Kenya by paleontologist Kamoya Kimeu. Turkana Boy's anatomy revealed a body type surprisingly close to ours — he may have reached 6 feet (1.85 meters) tall and 150 pounds (68 kilograms) if he had reached adulthood; he had a large brain; and he was fully adapted for efficient walking and running.

While Nariokotome Boy was likely one of our collective ancestors, two divergent branches of our family tree also have famous members: the "Hobbits," found on the island of Flores in Indonesia, and Homo naledi, from the Rising Star Cave in South Africa.

Skeletons found in a cave in Indonesia in 2004 surprised researchers because of their tiny size and their comparatively recent time frame: 700,000 to 50,000 years ago. At just 3 feet, 6 inches tall (1.06 meters), the members of the newly identified species, Homo floresiensis, were nicknamed "Hobbits," and one female was named "Flo". These individuals created stone tools and walked upright, but other parts of their anatomy were more australopithecine-like, similar to Lucy. No clear explanation has been given for why the Hobbits were so small, but one guess is island dwarfism, where large animals evolve to be smaller over many generations when food is scarce.

Related: Lucy's last day: What the iconic fossil reveals about our ancient ancestor's last hours

Meanwhile, in South Africa, anthropologists discovered H. naledi deep in the Rising Star Cave system. The most complete individual was nicknamed Neo, which means "gift" in the Sesotho language. Neo was a large adult male, and bones from nearly every part of his body were found. H. naledi had a mix of ancient and modern anatomy — hands that were adapted for climbing and feet that were adapted for walking — that was surprising for a species that lived from 336,000 to 236,000 years ago.

While questions about Flo and Neo abound, some famous fossils are answering long-standing questions about our evolutionary history.

Neanderthals and hybrids

For many years after they were first identified in 1856, scientists thought Neanderthals were unintelligent, cave-dwelling brutes who contributed nothing to modern humans. But the discovery of Denisovans in Russia in 2010 and advances in ancient DNA analysis showed that modern humans, Neanderthals and Denisovans were actually "kissing cousins."

Bones from a 13-year-old girl nicknamed Denny were found in the Denisova cave and studied in 2018. Denny's genome showed that she had a Neanderthal mother and a Denisovan father, making her the first — and, to date, only — first-generation hybrid hominin ever discovered. Over the past 15 years, multiple studies have revealed that Neanderthals, Denisovans and Homo sapiens met and mixed many times, but 90,000-year-old Denny remains the poster child for interbreeding between archaic and modern humans.

Although Neanderthals survived for hundreds of thousands of years, they eventually went extinct. "Thorin," whose skull and teeth were found in France in 2015, may have been one of the last Neanderthals, around 42,000 years ago. Named after a dwarf in J. R. R. Tolkien's "The Hobbit," Thorin has provided evidence that Neanderthals died out because they were isolated. When researchers sequenced Thorin's genome, they found that his ancestors went 50,000 years without exchanging genes with other Neanderthals.

Denny and Thorin have revealed that, although archaic and modern humans did interact for thousands of years, eventually the Denisovans and Neanderthals disappeared as separate populations, although some of their genes live on in humans.

Some suits of armor were designed to impress rather than to protect; others were lifesaving tools used in battle, where they were tested against swords, spears and arrows. From the stiffened linen of ancient warriors, to the flexible chain mail of Roman soldiers, to the gleaming plate armor of medieval knights, armor has evolved over millennia to protect soldiers in battle.

But it comes at a cost: "Every suit of armor is a trade-off between mobility and defense," Barry Molloy, an archaeologist and ancient warfare expert at University College Dublin, told Live Science.

Nor is there a perfect suit of armor. "It's down to what tactics you're using, what weapons you're accompanying it with, and do you have a large or a small shield?" he said.

Here are seven suits of real battle armor from centuries past.

Dendra armor (3,500 years old)

The Dendra armor was unearthed in 1960 at an archaeological site near the village of Dendra in southern Greece. It dates to around 1500 B.C. during the Mycenaean era, which began in southern Greece in about 1750 B.C. and ended around 1050 B.C., soon after the Late Bronze Age collapse.

The armor consists of more than a dozen bronze plates tied together with leather straps. They encased a warrior in bronze from their neck to their knees, while additional pieces of bronze protected the shins and lower arms. Fragments of boar's teeth also indicate the warrior wore a Mycenaean boar's-tooth helmet.

Molloy has studied and worn a precise replica of the Dendra armor and another study revealed that the armor protected users in an 11-hour battle simulation inspired by the Trojan War.

Molloy said the helmet and large neck guard provided almost complete protection for the head and neck, but later developments in armor removed most of the neck protection and shifted most of the face protection to the helmet.

King Tut's armor (3,300 years old)

The Egyptian boy king Tutankhamun died in his late teens around 1323 B.C. This suit of leather armor was found in a box when his tomb, in the Valley of the Kings near Luxor, was opened in 1922.

Military training would have been a part of the young king's education, and it is possible — but not proven — that this armor was worn by Tutankhamun himself. The armor is now part of the collection at the Grand Egyptian Museum in Cairo. It consists of a tunic-like garment that covered the torso with thousands of small pieces of rawhide leather, which overlapped to form a fish-scale-like pattern.

Tomb paintings show King Tut wearing such armor while hunting and riding a chariot into battle. However, these may be symbolic portrayals; researchers don't think Tut was ever in combat.

"Fish scale" armor from China (2,500 years old)

This armor tunic was made from thousands of small leather pieces in China about 2,500 years ago.

It was discovered in a grave in the Yanghai cemetery on the edge of the Taklamakan Desert, and studies suggest it was a lightweight, "one-size-fits-all" garment for equipping a large army.

It is unusual for organic materials like leather to survive so long without rotting, and researchers think the extremely dry desert environment helped to preserve it.

Patrick Wertmann, an archaeologist at the University of Zürich, told Live Science in an email that the design of overlapping leather pieces may have been inspired by fish scales. He said he was building a reconstruction of the ancient suit of armor to test its functionality and other technological aspects.

"Lorica squamata" from Serbia (1,700 years old)

Fish-scale-style armor may have allowed for more mobility, and it was used for several centuries. Later examples include this Roman "lorica squamata" — Latin for "scale armor" — that was discovered at the Timacum Minus archaeological site in eastern Serbia.

Timacum Minus was a Roman fort until the fourth century, when it seems to have been sacked and burned by invading Goths.

Roman soldiers are now best known for their articulated suits of lorica segmentata, but different types of armor were used in various places throughout history. Researchers think lorica squamata may have signified seniority in the Roman army, and contemporary paintings and sculptures show Roman emperors wearing such armor.

Yoroi armor from Japan (700 years old)

Samurai were members of an aristocratic warrior caste in Japan. They served in the Imperial and noble courts from the 12th century until being abolished in the 19th century.

In that time, samurai wore several types of armor, but the best known may be the "ō-yoroi," which means "great armor" in Japanese. This type of armor was usually worn on horseback. It was made from panels of iron and leather that were intricately ornamented with lacquered designs.

Such suits of armor became prized family relics. According to legend, this yoroi was donated to a shrine near Kyoto in the 14th century by Ashikaga Takauji, the founder of the Ashikaga shogunate that ruled Japan between 1336 and 1573.

Related: 'Incredibly rare' 2nd-century Roman armor pieced together like an 'ancient jigsaw puzzle'

Kiribati armor (300 years old)

The warriors of the Pacific islands of Kiribati were not just inspired by fish — they actually wore fish as armor to protect themselves from weapons. The islands have limited resources, so the islanders used what they could, including thick layers of coconut matting and spiny helmets made from dried porcupine fish.

This type of armor has become associated with Kiribati, but researchers think it was also used on the nearby islands of Nauru and Tuvalu, probably in ritual duels that also featured swords edged with shark teeth. It is not known how long this type of armor was utilized, but European missionaries reported a decline in the use of traditional Kiribati armor in the 19th century.

Ned Kelly's armor (145 years old)

The armor used by the Australian bushranger Ned Kelly is not ancient, but it is authentic — Kelly was captured and hanged in 1880, and his armor shows the marks of being hit by 18 bullets.

According to the State Library Victoria, where the armor is on display, Kelly and other members of his gang devised the bulletproof armor in 1879. They then constructed individual suits from the steel blades of plows and wore them for a train robbery near the town of Glenrowan in June 1880.

The shock value of the suits of armor gave the Kelly gang a psychological advantage during the robbery, but they were also cumbersome to wear.

After taking hostages in a local hotel, the gang donned their armor for a 15-minute shoot-out with police. Although the armor protected Kelly's head and torso, he suffered several bullet wounds to his hands and legs that resulted in his capture, while the other members of his gang died during the siege.

Physics experiments have changed the world irrevocably, altering our reality and enabling us to take gigantic leaps in technology. From ancient times to now, here's a look at some of the greatest physics experiments of all time.

Conservation of energy

Energy conservation — the idea that energy cannot be created or destroyed, only transformed — is one of the most important laws of physics. James Prescott Joule demonstrated this rule, the first law of thermodynamics, when he filled a large container with water and fixed a paddle wheel inside it. The wheel was held in place by an axle with a string around it and then looped over a pulley and attached to a weight, which, when dropped, caused the wheel to spin. By sloshing the water with the wheel, Joule demonstrated that the heat energy gained by the water from the wheel's movement was equal to the potential energy lost by dropping the weight.

Measurement of the electron's charge

As the fundamental carriers of electric charge, electrons carry the smallest amount of electricity possible. But the particles are truly tiny, with a mass 1,838 times smaller than the already-minuscule proton.

So how could you measure the charge on something so small? Physicist Robert Millikan's answer was to drop electrically charged oil drops through the plates of a capacitor and adjust the voltage of the capacitor until the electric field it emitted produced a force on some of the drops that balanced out gravity — thus suspending them in the air. Repeating the experiment for different voltages revealed that, no matter the size of the drops, the total charge it carried was a multiple of a base number. Millikan had found the fundamental charge of the electron.

 "Gold foil experiment" revealing the structure of the atom

Once thought to be indivisible, the atom was slowly divided and split by a series of experiments during the late 19th and early 20th centuries. These included J.J. Thomson's 1897 discovery of the electron and James Chadwick's 1932 identification of the neutron. But perhaps the most famous of these experiments was Hans Geiger and Ernest Marsden's "gold foil experiment." Under the direction of Ernest Rutherford, the students fired positively charged alpha particles at a thin sheet of gold foil. To their surprise, the particles passed through, revealing that atoms consisted of a positively charged nucleus separated by a significant empty space by their orbiting electrons.

Nuclear chain reaction

By the mid-20th century, scientists were aware of the basic structure of the atom and that, according to Einstein, matter and energy were different forms of the same thing. This set the stage for the wartime work of Enrico Fermi, who in 1942 demonstrated that atoms could be split to release enormous quantities of energy.

While working at the University of Chicago with an experimental setup he called an "atomic pile," Fermi demonstrated the first-ever controlled nuclear fission reaction. Fermi fired neutrons at the unstable isotope uranium-235, causing it to split and release more neutrons in a growing chain reaction. The experiment paved the way for the development of nuclear reactors and was used by J. Robert Oppenheimer and the Manhattan Project to build the first atomic bombs.

Wave-particle duality

One of the most famous experiments in physics is also one that illustrates, with disturbing simplicity, the bizarreness of the quantum world. The experiment consisted of two slits, through which electrons would travel to create an interference pattern on a screen, like waves. Scientists were stunned when they placed a detector near the screen and found that its presence caused the electrons to switch their behavior to act instead as particles.

First performed by Thomas Young to demonstrate the wave nature of light, the experiment was later used by physicists in the 20th century to show that all particles, including photons, were both waves and particles at the same time — and they acted more like particles when they were being measured directly.

Splitting of white light into colors

White light is a mixture of all the colors of the rainbow, but before 1672, the composite nature of light was completely unknown. Isaac Newton determined this by using a prism that bent light of different wavelengths, or colors, by different amounts, decomposing white light into its composite colors. The result was one of the most famous experiments in scientific history and a discovery that, alongside other contributions by Newton, gave birth to the modern field of optics.

Discovery of gravity

In perhaps the most widely repeated story in all of science, Newton is said to have chanced upon the theory of gravity while contemplating under the shade of an apple tree. According to the legend, when an apple fell and struck him on the head, he supposedly yelled "Eureka!" as he realized that the same force that brought the apple tumbling to Earth also kept the moon in orbit around our planet and Earth circling the sun. That force, of course, would become known as gravity.

The story is slightly embellished, however. According to Newton's own account, the apple did not strike him on the head, and there's no record of what he said or if he said anything, at the moment of discovery. Nonetheless, the realization led Newton to develop his theory of gravity in 1687, which was updated by Einstein's theory of general relativity 228 years later.

Blackbody radiation

By the turn of the 20th century, many physicists — having advanced theories that explained gravity, mechanics, thermodynamics and the behavior of electromagnetic fields — were confident that they had conquered the vast majority of their field. But one troubling source of doubt remained: Theories predicted the existence of a "blackbody" — an object capable of absorbing and then remitting all incident radiation. The problem was that physicists couldn't find it.

In fact, data from experiments conducted with close approximations of black bodies — a box with a single hole whose inside walls are black — revealed that significantly less energy was emitted from blackbodies than classical theories led scientists to believe, especially at shorter wavelengths. The contradiction between experiment and theory became known as the "ultraviolet catastrophe."

The discovery prompted Max Planck to propose that the energy emitted by blackbodies wasn't continuous but rather split into discrete integer chunks called quanta. His radical proposal catalyzed the development of quantum mechanics, whose bizarre rules are completely unintuitive to observers living in the macroscopic world.

Einstein and the eclipse

Following its publication in 1915, Einstein's groundbreaking theory of general relativity briefly remained just that — a theory. Then, in 1919, astronomer Sir Arthur Eddington devised and completed stunning proof using that year's total solar eclipse.

Key to Einstein's theory was the notion that space — and, therefore, the path that light would follow through it — was warped by powerful gravitational forces. So, as the moon's shadow passed in front of the sun, Eddington recorded the position of nearby stars from his vantage point on the island of Principe in the Gulf of Guinea. By comparing these positions to those he had recorded at night without the sun in the sky, Eddington observed that they had been shifted slightly by the sun's gravity, completing his stunning proof of Einstein's theory.

Higgs boson

In 1964, Peter Higgs suggested that matter gets its mass from a field that permeates all of space, imparting particles with mass through their interactions with a particle known as the Higgs boson.

To search for the boson, thousands of particle physicists planned, constructed and fired up the Large Hadron Collider. In 2012, after trillions upon trillions of collisions in which two protons are smashed together at near light speed, the physicists finally spotted the telltale signature of the boson.

Weighing the world

Although he's perhaps best known for his discovery of hydrogen, 18th-century physicist Henry Cavendish's most ingenious experiment accurately estimated the weight of our entire planet. Using a special piece of equipment known as a torsion balance (two rods with one smaller and one larger pair of lead balls attached to the end), Cavendish measured the minuscule force of gravitational attraction between the masses. Then, by measuring the weight of one of the small balls, he measured the gravitational force between it and Earth, giving him an easy formula for calculating our planet's density and — therefore, its weight — that remains accurate to this day.

Conservation of mass

Much like energy, matter in our universe is finite and cannot be created or destroyed, only rearranged. In 1789, to arrive at this startling conclusion, French chemist Antoine Lavoisier placed a burning candle inside a sealed glass jar. After the candle had burned and melted into a puddle of wax, Lavoisier weighed the jar and its contents, finding that it had not changed

Leaning Tower of Pisa experiment

Greek philosopher Aristotle believed that objects fall at different rates because the force acting upon them was stronger for heavier objects — a claim that went unchallenged for more than a millennium.

Then came the Italian polymath Galileo Galilei, who corrected Aristotle's false claim by showing that two objects with different masses fall at exactly the same rate. Some claim Galileo's famous experiment was conducted by dropping two spheres from the Leaning Tower of Pisa, but others say this part of the story is apocryphal. Nonetheless, the experiment was perhaps most famously demonstrated by Apollo 15 astronaut David Scott, who, while dropping a feather and a hammer on the moon, showed that without air, the two objects fell at the same speed.

Detection of gravitational waves

If gravity warps space-time as Einstein predicted, then the collision of two extremely dense objects, such as neutron stars or black holes, should also create detectable shock waves in space that could reveal physics unseen by light. The problem is that these gravitational waves are tiny, often the size of a few thousandths of a proton or neutron, so detecting them requires an extremely sensitive experiment.

Enter LIGO, the Laser Interferometer Gravitational-Wave Observatory. The L-shaped detector has two 2.5-mile-long (4 km) arms containing two identical laser beams. When a gravitational wave laps at our cosmic shores, the laser in one arm is compressed and the other expands, alerting scientists to the wave's presence. In 2015, LIGO achieved its task, making the first-ever direct detection of gravitational waves and opening up an entirely new window to the cosmos.

Destruction of heliocentrism

The idea that Earth orbits the sun goes back to the fifth century B.C. to Greek philosophers Hicetas and Philolaus. Nonetheless, Claudius Ptolemy's belief that Earth was the center of the universe later took root and dominated scientific thought for more than a millennium.

Then came Nicolaus Copernicus, who proposed that Earth did, in fact, revolve around the sun and not the other way around. Concrete evidence for this was later offered by Galileo, who in 1610 peered through his telescope to observe the planet Venus moving through distinct phases — proof that it, too, orbited the sun. Galileo's discovery did not win him any friends with the Catholic Church, which tried him for heresy for his unorthodox proposal.

Foucault's pendulum

First used by French physicist Jean Bernard Léon Foucault in 1851, the famous pendulum consisted of a brass bob containing sand and suspended by a cable from the ceiling. As it swung back and forth, the angle of the line traced out by the sand changed subtly over time — clear evidence that some unknown rotation was causing it to shift. This rotation was the spinning of Earth on its axis.

Discovery of the electron

In the 19th century, physicists found that by creating a vacuum inside a glass tube and sending electricity through it, they could make the tube give off a fluorescent glow. But exactly what caused this effect, called a cathode ray, was unclear.

Then, in 1897, physicist J.J. Thomson discovered that by applying a magnetic field to the rays inside the tube, he could control the direction in which they traveled. This revelation showed Thomson that the charge within the tube came from tiny particles 1,000 times smaller than hydrogen atoms. The tiny electron had finally been found.

Deflection of an asteroid

In 2022, NASA scientists hit an astronomical "bull's-eye" by intentionally steering the 1,210-pound (550 kilograms), $314 million Double Asteroid Redirection Test (DART) spacecraft into the asteroid Dimorphos just 56 feet (17 meters) from its center. The test was designed to see if a small spacecraft propelled along a planned trajectory could, if given enough lead time, redirect an asteroid from a potentially catastrophic impact with Earth.

DART was a smashing success. The probe's original goal was to change the orbit of Dimorphos around its larger partner — the 2,560-foot-wide (780 m) asteroid Didymos — by at least 73 seconds, but the spacecraft actually altered Dimorphos' orbit by a stunning 32 minutes. NASA hailed the collision as a watershed moment for planetary defense, marking the first time that humans proved capable of diverting Armageddon, and without any assistance from Bruce Willis.

Faraday induction

In 1831, Michael Faraday, the self-taught son of a blacksmith born in rural south England, proposed the law of electromagnetic induction. The law was the result of three experiments by Faraday, the most notable of which involved the movement of a magnet inside a coil made by wrapping a wire around a paper cylinder. As the magnet moved inside the cylinder, it induced an electric current through the coil — proving that electric and magnetic fields were inextricably linked and paving the way for electric generators and devices.

Measurement of the speed of light

Light is the fastest thing in our universe, which makes measuring its speed a unique challenge. In 1676, Danish astronomer Ole Roemer chanced upon the first estimate for light's propagation while studying Io, Jupiter's innermost moon. By timing the eclipses of Io by Jupiter, Roemer was hoping to find the moon's orbital period.

What he noticed instead was that, as Earth's orbit moved closer to Jupiter, the time intervals between successive eclipses became shorter. Roemer's crucial insight was that this was due to a finite speed of light, which he roughly calculated based on Earth's orbit. Other methods later refined the measurement of light's speed, eventually arriving at its current value of 2.98 × 10^8 meters per second (about 186,282 miles per second).

Disproof of the "luminiferous ether"

Most waves, such as sound waves and water waves, require a medium to travel through. In the 19th century, physicists thought the same rule applied to light, too, with electromagnetic waves traveling through a ubiquitous medium dubbed the "luminiferous ether."

Albert Michelson and Edward W. Morley set out to prove this conjecture with a remarkably ingenious hypothesis: As the sun moves through the ether, it should displace some of the strange substance, meaning light should travel detectably faster when it moves with the ether wind than against it. They set up an interferometer experiment that used mirrors to split light beams along two opposing directions before bouncing them back with distant mirrors. If the light beams returned at different times, then the ether was real.

But the light beams inside their interferometer did not vary. Michelson and Morley concluded that their experiment had failed and moved on to other projects. But the result — which had conclusively disproved the ether theory — was later used by Einstein in his theory of special relativity to correctly state that light's speed through a fixed medium does not change, even if its source is moving.

Discovery of radioactivity

In 1897, while working in a converted shed with her husband Pierre, Marie Curie began to investigate the source of a strange new type of radiation emitted from the elements thorium and uranium. Marie Curie discovered that the radiation these elements emitted did not depend on any other factors, such as their temperature or molecular structure, but changed purely based on their quantities. While grinding up an even more radioactive substance known as pitchblende, she also discovered that it consisted of two elements that she dubbed radium and polonium.

Curie's work revealed the nature of radioactivity, a truly random property of atoms that comes from their internal structure. Curie won the Nobel Prize (twice) for her discoveries — making her the first woman to do so — and later trained doctors to use X-rays to image broken bones and bullet wounds. She died of aplastic pernicious anemia, a disease caused by radiation exposure, in 1934.

Expansion of the universe

While using the 100-inch Hooker telescope in California to study the light glimmering from distant galaxies in 1929, Edwin Hubble made a surprising observation: The light from the distant galaxies appeared to be shifted toward the red end of the spectrum — an indication that they were receding from Earth and each other. The farther away a galaxy was, the faster it was moving away.

Hubble's observation became a crucial piece of evidence for the Big Bang theory of our universe. Yet precise measurements for galaxies' recession, known as the Hubble constant, still confound scientists to this day.

Put simply, the universe is indeed expanding, but depending on where cosmologists look, it's doing so at different rates. In the past, the two best experiments to measure the expansion rate were the European Space Agency's Planck satellite and the Hubble Space Telescope. The two observatories, each of which used a different method to measure the expansion rate, arrived at different results. These conflicting measurements have led to what some call a "cosmology crisis" that could reveal new physics or even replace the standard model of cosmology.

Ignition of nuclear fusion

In 2022, scientists at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory in California used the world's most powerful laser to achieve something physicists have been dreaming about for nearly a century: the ignition of a pellet of fuel by nuclear fusion.

The demonstration marked the first time that the energy going out of the plasma in the nuclear reactor's fiery core exceeded the energy beamed in by the laser, and has been a rallying call for fusion scientists that the distant goal of near-limitless and clean power is, in fact, achievable.

However, scientists have cautioned that the energy from the plasma exceeds only that from the lasers, and not from the energy from the whole reactor. Additionally, the laser-confinement method used by the NIF reactor, built to test thermonuclear explosions for bomb development, will be difficult to scale up.

Measurement of Earth's circumference

By roughly 500 B.C., most ancient Greeks believed the world was round — citing evidence provided by Aristotle and guided by a suggestion from Pythagoras, who believed a sphere was the most aesthetically pleasing shape for our planet.

Then, around 245 B.C., Eratosthenes of Cyrene thought of a way to make the measurement directly. Eratosthenes hired a team of bematists (professional surveyors who measured distances by walking in equal-length steps called stadia) to walk from Syene to Alexandria. They found that the distance between the two cities was roughly 5,000 stadia.

Eratosthenes then visited a well in Syene that had been reported to have an interesting property: At noon on the summer solstice each year, the sun illuminated the well's bottom without casting any shadows. Eratosthenes went to Alexandria during the solstice, stuck a pole in the ground and measured the shadow from it to be about one-fiftieth of a complete circle. Pairing this with his measurement of the distance between the two cities, he determined that Earth's circumference was about 250,000 stadia, or 24,497 miles (39,424 km). Earth is now known to measure 24,901 miles (40,074 km) around the equator, making the ancient Greeks' measurements remarkably accurate.

Discovery of black holes

The acceptance of Einstein's theory of general relativity led to some startling predictions about our universe and the nature of reality. In 1915, Karl Schwarzschild's solutions to Einstein's field equations predicted that it was possible for mass to be compressed into such a small radius that it would collapse into a gravitational singularity from which not even light could escape — a black hole.

Schwarzschild's solution remained speculation until 1971, when Paul Murdin and Louise Webster used NASA's Uhuru X-ray Explorer Satellite to identify a bright X-ray source in the constellation Cygnus that they correctly contended was a black hole.

More conclusive evidence came in 2015, when the LIGO experiment detected gravitational waves from two of the colliding cosmic monsters. Then, in 2019, the Event Horizon Telescope captured the first image of the accretion disk of superheated matter surrounding the supermassive black hole at the center of the galaxy M87.

Discovery of X-rays

While testing whether the radiation produced by cathode rays could escape through glass in 1895, German physicist Wilhelm Conrad Röntgen saw that the radiation could not only do so, but it could also zip through very thick objects, leaving a shadow on a lead screen placed behind them. He quickly realized the medical potential of these rays — later known as X-rays — for imaging skeletons and organs. His observations gave birth to the field of radiology, enabling doctors to safely and noninvasively scan for tumors, broken bones and organ failure.

The Bell test

In 1964, physicist John Stewart Bell proposed a test to prove that quantum entanglement — the weird instantaneous connection between two far-apart particles that Einstein objected to as "spooky action at a distance" — was required by quantum theory.

The test has taken many experimental forms since Bell first proposed it, but the findings remain the same: Despite what our intuition tells us, what happens in one part of the universe can instantaneously affect what happens in another, provided the objects in each region are entangled.

Detection of the quark

In 1968, experiments at the Stanford Linear Accelerator Center found that electrons and their lepton cousins, muons, were scattering from protons in a distinct way that could only be explained by the protons being composed of smaller components. These findings matched predictions by physicist Murray Gell-Mann, who dubbed them "quarks" after a line in James Joyce's "Finnegans Wake."

Archimedes' naked leap from his bathtub

First recorded in the first century B.C. by Roman architect Vitruvius, Archimedes' discovery of buoyancy is one of the most famous stories in science. The prompting for Archimedes' finding came from King Hieron of Syracuse, who suspected that a pure-gold crown a blacksmith made for him actually contained silver. To get an answer, Hieron enlisted Archimedes' help.

The problem stumped Archimedes, but not long after, as the story goes, he filled up a bathtub with water and noticed that the water spilled out as he got in. This caused him to realize that the water displaced by his body was equal to his weight — and because gold weighed more than silver, he had found a method for judging the authenticity of the crown. "Eureka!" ("I've got it!") Archimedes is said to have cried, leaping from his bathtub to announce his discovery to the king.

Deepest and most detailed photo of the universe

In 2022, the James Webb Space Telescope unveiled the deepest and most detailed picture of the universe ever taken. Called "Webb's First Deep Field," the image captures light as it appeared when our universe was just a few hundred million years old, right when galaxies began to form and light from the first stars started flickering.

The image contains an overwhelmingly dense collection of galaxies, the light from which, on its way to us, was warped by the gravitational pull of a galaxy cluster. This process, known as gravitational lensing, brings the fainter light into focus. Despite the dizzying number of galaxies in view, the image represents just a tiny sliver of sky — the speck of sky blocked out by a grain of sand held on the tip of a finger at arm's length.

OSIRIS-REx asteroid-sampling mission

In 2023, NASA's OSIRIS-REx spacecraft came hurtling back through Earth's atmosphere after a years-long journey to Bennu, a "potentially hazardous asteroid" with a 1-in-2,700 chance of smashing cataclysmically into Earth — the highest odds of any identified space object.

The goal of the mission was to see whether the building blocks for life on Earth came from outer space. OSIRIS-REx circled the asteroid for 22 months to search for a landing spot, touching down to collect a 2-ounce (60 grams) sample from Bennu's surface that could contain the extraterrestrial precursors to life on our planet. Scientists have already found many surprising details that have the potential to rewrite the history of our solar system.

As one of Earth's closest neighbors in space, Mars has long captivated humans with the prospect of alien life located just a short rocket trip away. No such life has been found. But now, as NASA and other space agencies have begun to explore the skies and surface of the Red Planet using robotic technology, images of strange features and formations continue to inflame skywatchers' hopes, fears and curiosities.

Here are some of our favorite objects on Mars that look like they don't belong on a dead and dusty planet. Many of these are a result of pareidolia — the tendency for humans to seek familiar patterns and shapes in inanimate objects. However, some of them may even lead scientists to the long-sought evidence of past Martian life.

An open "travel book"

Perhaps weary from hunting for evidence of ancient water, NASA's Curiosity rover took a short break in April 2023 to leaf through the pages of an old Martian hardback lying in the dust of Gediz Vallis. While the strange object may look like a book with a single page frozen mid-turn, it is in fact just a rock — and a small one at that. The charming little book-rock measures just 1 inch (2.5 centimeters) wide, according to NASA. Hey, at least it's travel-size!

Related: 'Spiders on Mars' fully awakened on Earth for 1st time — and scientists are shrieking with joy

A "teddy bear's face"

In an image shared in January 2023 by the University of Arizona (UA), what appears to be the face of an enormous Martian teddy bear — complete with two beady eyes, a button nose and an upturned mouth — grins at the camera of NASA's Mars Reconnaissance Orbiter. According to UA, the cuddly-wuddly formation is likely just a broken-up hill in the center of an ancient crater. But as far as we're concerned, it's the cutest pile of rubble in the known universe.

Frozen "mineral flowers"

Branching outward like a tiny coral, this delicate mineral flower is about the closest thing to greenery one can find on the Red Planet today. Mineral deposits like these are common sights across Mars and result from ancient water mixing with ancient rock. Still, it's rare to see a deposit that's so perfectly flower-like, NASA researchers said. You'll notice two slightly less impressive, circular rocks of the same type to the right of the coral. Curiosity spotted this floral feature in February 2022.

A mysterious "doorway"

Is this perfectly hewn "doorway" into a Martian cliffside evidence of intelligent alien life on the Red Planet — or perhaps signs of a secret society of human astronauts camped out in clandestine Mars bunkers? Sadly (for conspiracy theorists), the truth is far simpler: It's just an eroded rock formation caught at the perfect angle. The image was captured by NASA's Curiosity rover in 2022.

Fossilized "animal tracks"

Did alien creatures once skitter across the surface of Mars, leaving fossilized tracks embedded in the rocks? One researcher made this controversial claim in 2018, pointing to images of stick-like structures, each about the size of a grain of rice, crisscrossing a Martian rock. NASA researchers quickly debunked the claims, noting that similar features are plentiful on Earth in areas where salts become concentrated in water, such as evaporating lakes. Their presence on Mars is yet more evidence of past rivers and lakes on the Red Planet, but they offer no proof that living creatures ever adorned its surface.

A bushel of "blueberries"

Blueberries are not a significant source of iron when consumed on Earth — but these geological "blueberries" discovered by NASA's Opportunity rover on Mars in 2004 are built differently. The iron-rich spheres, polished smooth by plentiful amounts of water billions of years ago, are some of the earliest evidence scientists have of Mars once being an incredibly wet world. Whether they also taste good on cheesecake is a question for future generations to grapple with.

Thousands of black "spiders on Mars"

Every spring, thousands of squiggly black "spiders" emerge from their hibernation near the Martian south pole. No, they are not real spiders — they are not alive at all, of course. The seasonal phenomenon is a result of buried carbon dioxide ice sublimating, or turning to gas, as the weather warms. The newly released gas bursts through layers of surface ice, carrying with it dark dust that splatters across the ground in craggy patterns. To be visible from space, as these formations are, the "spiders" must be fairly big — each one measuring 150 to 3,300 feet (45 meters to 1 kilometer) across, according to the European Space Agency (ESA). Please, nobody tell Ziggy Stardust the bad news.

Ruins of an "Inca City"

Near the Martian south pole are curious structures that look like the ruins of a vast and ancient city. Dubbed the "Inca City" for its resemblance to actual ruins discovered in South America, the bizarre rock formation may be made of elevated sand dunes that turned to stone over time, according to ESA. However, its exact origins remain a mystery. The labyrinthine formation appears to curve, forming part of a giant circle 53 miles (86 km) in diameter, leading scientists to suspect it may be part of a much larger impact crater from a meteor strike ages ago.

An ancient smiley face

Did someone spray-paint a grinning face onto the Martian surface? Not quite, despite what it looks like in this infrared image snapped by ESA's ExoMars Trace Gas Orbiter. Visible only under certain conditions, the face seen here is actually the remnants of an ancient lake, outlined by chloride salt deposits and dotted with two meteor crater eyes. While no Martian graffiti artists are going to pop up from the lake to claim their work, the face-like structure could contain evidence of ancient life on the Red Planet. As Mars' once-plentiful lakes dried up, the remaining water sources likely became very salty, possibly offering a haven for microbial life.

An extremely out-of-place rock

One of these things is not like the other. Standing out like a sore Martian thumb inside dusty Jezero Crater, this unusually white rock is the first of its kind ever seen on the Red Planet. Dubbed "Atoko Point" after a similarly light-colored feature of the Grand Canyon, the speckled rock is likely made of the minerals pyroxene and feldspar, according to an analysis by NASA's Perseverance rover. How did such a white rock find itself in such dark-hued company? It likely tumbled down from the crater rim or was transported to the crater floor from elsewhere on Mars back when rivers raged across the region.

A stony "Star Trek" symbol

Looks like someone from Starfleet left their communicator badge on the Red Planet — or so it would appear from the familiar shape of this rock spotted by the Curiosity rover. The rock's delta shape is just a coincidence, according to NASA. It is one of thousands located on Mount Sharp, which Curiosity has been exploring for years in its search to uncover clues about Mars' past and whether it ever held the conditions for life.

A "tile floor"

While scaling the slopes of Mount Sharp in 2021, NASA's Curiosity rover found remnants of what looks like a tile floor from a Martian bathroom. Dozens of interlocked polygons cracked through the dirt; most contain five or six sides and date to between 3.8 billion and 3.6 billion years ago. These jagged polygons are mud cracks, which have repeatedly dried out and moistened again over the course of untold years. They likely date to a time when the water level in the surrounding Gale Crater rose and fell repeatedly, causing the polygonal cracks in the ground to appear and disappear over time before a final dry spell left them as they are today.

Perfectly circular sand dunes

Mars is covered in dunes of all shapes and sizes, but few of them are as perfectly circular as the group spotted above by NASA's Mars Reconnaissance Orbiter in 2022. Snapped while flying over Mars' northern hemisphere, the image shows a bubbling patchwork of dark and strangely round dunes, slanting southward in the direction where the Martian wind likely blew them. Scientists are still not certain why these particular dunes are so circular or why they appear to be slowly migrating away from Mars' equator at a rate of roughly 3.3 feet (1 m) per Martian year (687 days on Earth).

A "shark fin" and a "crab claw"

While trawling through Jezero Crater, NASA's Perseverance rover caught sight of a few fishy-looking rocks. The two odd boulders — one jutting upward like a shark fin, and the other crimped like a crab claw — surprised researchers. However, there isn't much mystery to them. They are just rocks, sculpted by the wind over billions of years and left in the Martian dust for pattern-seeking human minds to find.

A "floating spoon"

In 2015, NASA's Curiosity rover spotted what appeared to be a wooden spoon, floating in midair with a shadow on the ground beneath it. It was, of course, an optical illusion; the spoon is simply a rock, shaped by the wind over eons, also known as a ventifact. The handle of the spoony rock juts out from a larger formation, allowing the spoon's rounded tip to hover over the ground below, casting a distinct shadow beneath it.

An eerie "face"

One of the earliest Martian rock formations to capture the public's interest was this infamous "face" spotted by NASA's Viking 1 satellite in 1976. While circling the planet looking for a landing site for its robotic companion, Viking 2, the satellite spotted a mound of rocks, partially obscured in shadow, distinctly resembling a human face. Follow-up observations with later spacecraft showed that the face was visible only from certain angles and under certain light conditions, proving that the Martian mound's humanlike appearance was just a trick of light and shadow.

A "giant's fingerprint"

A long time ago, something slammed into the surface of Mars and left this enormous, ridged, thumbprint-like depression behind. A giant finger was not the culprit, of course. Located inside a much larger crater called Airy-0, this Martian hole is the result of an ancient meteor impact. The bright striations forming the "lines" of the fingerprint are a common sight across Mars. Known as transverse aeolian ridges, they are created when sand dunes get coated in a thin layer of dust. The dust likely contains reflective minerals, giving the depression its glowing appearance in this image.

A rock with an, er … crack

Try not to laugh at this rock snapped by NASA's Perseverance rover in 2021. The cracked boulder became the butt of more than a few jokes after its close-up was first released to the public. There's really not much to see, though — the Red Planet is full of cracked rocks, albeit not quite as plump as this one. Perseverance spotted this rock in dusty Jezero Crater, on its 102nd day on Mars.

An "angel" and a heart

When it's summertime on Mars, the angels come out to play. The Martian south pole is usually covered in an enormous ice cap, but when the ice melts in warmer weather, patterns in the ancient, red-hued sediment below come to light. This image, snapped by ESA's Mars Express spacecraft, shows an angel-like pattern next to a heart-shaped one. Both of these familiar-looking structures are the result of meteor impact craters that scraped away Mars' dusty topsoil to reveal the darker sediment below.

A weirdly green rock with "drill holes"

Did a bored Martian teenager get a hold of his parents' power tools again? That is one (unlikely) explanation for a strange, green rock seemingly pumped full of drill holes that was spotted by NASA's Perseverance rover early in its mission. The roughly 6-inch (15 cm) rock looks out of place in its environment, and scientists aren't totally sure how to explain it. Perhaps it is the remnant of a meteor that collided with the Red Planet, or maybe it is a piece of Martian bedrock that was flung far across the world during an impact event. Most of the holes are also a mystery — but, if you look just right of center, you may see a small train of tiny, uniform pockmarks left by Perseverance's laser, which it fired at the rock while trying to analyze its composition.

A small "foreign object"

A small, rectangular object spotted in Mars' Gale Crater in 2018 briefly gave NASA scientists a scare. Looking vaguely like a dusty sheet of metal, the object was potentially thought to be a chunk of the Curiosity rover that had inexplicably fallen off. Luckily, a quick analysis showed that the "foreign object," as NASA initially dubbed it, was just a flake of rock that had split off of a larger formation and wasn't foreign to Gale Crater at all.

A strange, white tower

Towering over the Martian horizon in an image captured by NASA's Perseverance rover in 2023, a tall, white column stands against the dark, rocky background. It is, in fact, a Martian dust devil. And it's an enormous one: The dusty vortex captured here is taller than an average tornado on Earth and five times taller than the Empire State Building, according to NASA. Formed when rising cells of warm air meet falling columns of cool air, dust devils are exceedingly common on Mars — perhaps numbering as many as 145 million per day, one 2018 study estimated.

A "scar" longer than the Grand Canyon

Gaping like a fresh wound in this image captured by ESA's Mars Express orbiter in 2024, the Martian feature known as Aganippe Fossa is a sight to behold. The deep, dark ravine stretches around 375 miles (600 km) long — longer than the Grand Canyon, which measures about 277 miles (446 km) long. Located near the base of an extinct volcano, the Martian canyon likely formed as the result of ancient volcanic activity — possibly when a large pool of magma beneath the volcano pushed violently upward, tearing the ground asunder, according to ESA.

"Rock candy," or ultra-rare crystals?

These strangely colored crystals on Mars were discovered by pure accident. In May 2024, NASA's Curiosity rover drove over a small rock in its path, unintentionally crushing it. Buried within the stone tomb was a cache of rare minerals, including some never seen before on the Red Planet. The yellowish crystals are made of pure elemental sulfur. Scientists had long expected that this material existed on Mars but had no proof until Curiosity's bout of destructive driving.

A "bullet" hole

What looks like a hole blasted into the Martian landscape by a stray bullet may be something much more exciting — a possible refuge for future astronauts. The hole, which measures a few meters across, was imaged by NASA's Mars Reconnaissance Orbiter in 2022 on the flank of a massive volcano called Arsia Mons. The pit is located along a lava flow and appears to be a vertical shaft that could potentially connect to a deep system of caverns below the volcano. Although the hole's depth is unknown, it may be a tempting refuge for future astronauts who need a place to shield themselves from the intense radiation that beams down on the Red Planet.

An underground "dog"

Strange structures don't appear only on Mars' surface but underground as well. In September 2024, researchers combined data from several Mars-orbiting spacecraft to create a planet-wide map of gravitational anomalies — places where the pull of gravity is stronger than average, suggesting the presence of massive, dense structures located under the planet's surface. Most of these dense blobs are amorphous, but one caught the researchers' attention: a strange, dog-shaped structure, with a dark tail and ears, located near the Martian north pole. It's unclear how the dense, doggy structure formed, but it could be related to a past meteor impact or a pile-up of volcanic material.

Debris from outer space?

Nestled among the dusty, red rocks of Gale Crater, a jagged, gray object instantly caught the attention of scientists operating NASA's Curiosity rover. The shrapnel-like rock looks out of place because it almost certainly is — according to researchers, the pointy boulder is probably the remnant of a meteorite that crash-landed on Mars' surface ages ago. Dubbed Ames Knob and measuring about 4 inches wide by 5.5 inches long (10 by 14 cm), this meteorite isn't just space trash; according to NASA researchers, studying the rock could help reveal the past conditions on the planet when the meteorite fell, including whether it landed on land or in now-vanished water.

Debris … from Earth?

In 2022, NASA spotted what looked like the wreck of an "alien" spacecraft on Mars. In this case, the "aliens" were, in fact, Earthlings; the wreckage seen by NASA's Ingenuity Mars helicopter was a piece of the helicopter's own parachute and backshell, a saucer-like cover that helped slow the robotic craft's descent as it dropped onto the Red Planet along with the larger Perseverance rover. This piece of wrecked human technology, photographed by Ingenuity while it was flying 26 feet (8 m) above the Martian surface, looks particularly alien amid the desolate rocks and dust of the surrounding landscape.

An alien "egg"?

From certain angles, this pockmarked rock looks like an oozing, green egg belonging to some unknown alien monster. But a quick analysis from NASA's Curiosity rover revealed that the odd boulder — dubbed Egg Rock — is actually a fragment of a meteorite that landed on the Red Planet at some unknown time in the past. Studying Martian meteorites like this one can reveal valuable clues about the planet's past but is unlikely to lead back to any extraterrestrial monster nests.

Swirling patterns

Strange patterns carved into the surface of Mars' Nili Fossae region aren't alien sand art or the Martian version of Peru's Nazca Lines. They are, in fact, mineral deposits containing large quantities of olivine, a mineral typically only found deep below the surface of Mars. How did so much olivine-rich rock reach the planet's surface? That question presents a tempting mystery for scientists. It could be that a huge asteroid impact excavated the Martian interior, bringing olivine to the surface in swirling splatters — or perhaps the subsurface mineral saw daylight following a massive volcanic eruption. Its precise origin remains a mystery to this day.

An alien monolith?

When amateur stargazers were looking through images from NASA's Mars Reconnaissance Orbiter, they spotted something strange in the satellite's data: a bizarrely rectangular object reminiscent of the alien monolith from the opening scene of "2001: A Space Odyssey." The perplexing feature is indeed monolithic in shape and size, according to mission scientists. However, it is likely nothing more than a big, perfectly rectangular rock.

A crawling robot

Spotted from miles above by NASA's Mars Reconnaissance Orbiter, a crawling metallic robot glints on the Martian surface far below. This is a rare case where the mystery object is exactly what it looks like; that robot is NASA's Curiosity rover, making its way up Mount Sharp several years into its mission to explore the Red Planet. Concrete evidence that Mars ever held life is still lacking — but at least we can say Mars is the only known planet in the universe inhabited exclusively by robots.

Far beyond the eight familiar planets in our solar system, countless bizarre and extreme worlds await discovery — and some have already been found.

Thanks to rapidly advancing telescope technology, astronomers have detected more than 5,600 planets outside our solar system. These exoplanets, as scientists call them, are worlds of lava, and worlds of water. They're worlds being ravaged by the heat of their stars, and worlds locked in eternal night. There are worlds that look like they were stolen straight from "Star Wars," and worlds that may hold exotic forms of life never dreamed up in science fiction.

Join us as we tour some of the strangest and most fascinating exoplanets in our ever-surprising universe.

The "hell planet" where it rains lava

55 Cancri e is a rocky world about eight times the size of Earth, making it a type of exoplanet known as a "super Earth." Despite its ample size, nothing is "super" about the living conditions here. Often nicknamed the "hell planet," 55 Cancri e is completely covered in flowing seas of lava, and it may even rain lava there as well. The exoplanet is located 41 light-years from Earth, making it a popular target for studies (but not for summer getaways).

Related: 38 jaw-dropping James Webb Space Telescope images

The water world with (potentially) living oceans

K2-18 b is a large world located about 120 light-years from the sun. It inhabits the "Goldilocks zone" around its star, meaning that liquid water (and potentially life) could exist there. A recent analysis with the James Webb Space Telescope (JWST) supports the idea that the exoplanet may have its own liquid water ocean — and that the ocean may be home to living creatures. In the study, JWST detected possible traces of dimethyl sulfide, a chemical known to be emitted only by phytoplankton on Earth, in the exoplanet's atmosphere.

The real-world "Tatooine"

Luke Skywalker would feel right at home on Kepler-16b. This exoplanet is the first known circumbinary planet — a planet that orbits two stars at the same time, just like Tatooine from the Star Wars franchise. However, because this huge planet has a gassy surface similar to Saturn's, even a Jedi would have a hard time finding their footing on this exoplanet, which is located about 200 light-years from the sun.

The rule-breaking behemoth

The giant exoplanet LHS 3154b has scientists scratching their heads, because it seems far too large for its tiny star. This planet, which is about 13 times more massive than Earth but orbits a star nine times less massive than the sun, doesn't seem like it could exist, researchers said upon its discovery in 2023. Future studies of this "impossible" world could upend the known rules of planet formation.

The largest exoplanet in the known universe?

With twice the radius of Jupiter, the exoplanet HAT-P-67 b may be the largest known planet in the universe, in terms of width. But despite its monumental girth, there are more massive worlds out there. This honkin' world, located about 1,200 light-years from Earth, has a very low density, giving it only about one-third the mass of Jupiter.

The "fluffy" planet where it rains sand

Located 200 light-years from Earth, the exoplanet WASP-107b also has a very low density, making it appear "fluffy" in telescope observations. A recent JWST study of the planet revealed clouds potentially made of fine-grained silicate particles, meaning it may literally rain sand on this puffed-up world.

The "eyeball planet" with potentially living seas

Sitting just 50 light-years from Earth, the beady-eyed exoplanet LHS 1140 b may be a candidate for alien life thanks to its one-of-a-kind surface. Scientists studying the world with JWST found that the planet may be covered in ice — except for the one part of its surface that permanently points toward its host star. Here, the star's heat may melt just enough ice for a circular, liquid water ocean to form, according to the researchers. Besides giving the planet a distinct bull's-eye appearance, this rare ocean may be a prime place for extraterrestrial life to flourish, the team wrote.

The rotten-egg world

The exoplanet HD 189733 b, located about 64 light-years from Earth, has a chemical composition so distinct that astronomers can practically smell it from across the galaxy. A recent JWST study of the planet found that its atmosphere contains significant amounts of hydrogen sulfide — a toxic and flammable gas given off by decaying organic matter and volcanoes on Earth — which smells like rotten eggs. The smelly egg planet is far too hot for life to exist (thank goodness), but the mere fact that scientists can detect such distinct molecules in its atmosphere is a good sign that JWST may soon be able to detect signatures of life elsewhere in the universe.

The "Vulcan planet" that may not exist

In a remarkable case of science fiction reflected in reality, scientists have reported the discovery of a planet similar to Vulcan, the home world of Dr. Spock in the Star Trek franchise. The planet was discovered in 2018 around the real star 40 Eridani A — the very same star that hosts Spock's home planet in the famous sci-fi series. However, recent follow-up observations of the star have called the planet's existence into question; subtle wobbles in the star's light signature may result not from a nearby planet's tugging on it but rather from regular eruptions on the star's surface. The existence of the Vulcan planet, named HD 26965 b, now seems in doubt.

The Earth-like planet around a small, red star

Earth may have a long-lost twin in a nearby star system. Named Gliese 12 b, the planet orbits a hot, red star in a system roughly 40 light-years from Earth. Remarkably, the exoplanet appears to have a width 1.1 times that of Earth, giving it similar properties to our own planet. And while Gliese 12 b orbits its home star much more closely than our planet does the sun (one year there lasts about 13 Earth days), that star is also much smaller, keeping the planet in the habitable zone where liquid water can form on the planet's surface. That means our distant twin may even have its own version of life.

The Earth-size planet with eternal night

Not all Earth-size planets are lucky enough to be habitable. Take SPECULOOS-3 b, a rocky, Earth-like world whose orbit around its red dwarf star is a little too close for comfort. Completing an orbit every 17 hours, the rocky world is exposed to so much radiation that its atmosphere was likely blasted away long ago, leaving the unlucky planet totally barren. The roasting temperatures aren't a global phenomenon, however; this planet is tidally locked, meaning one side always faces its star in eternal day, while the other side sits in perpetual night.

The red volcano world that's "melting from within"

Astronomers have discovered a planet in a distant star system that appears to be erupting with so many volcanoes, the world literally glows red when seen through telescopes. The smoldering exoplanet, named TOI-6713.01, is located roughly 66 light-years from Earth and orbits its star closely, completing a loop every 2.2 Earth days. Observations suggest the planet is covered in molten lava, released by hundreds of active volcanoes. The planet is also subject to incredible internal friction from the gravity of its star and its neighboring planets, which may be causing the world to literally melt from within.

The gas giant with bullet-like wind

Scientists have mapped the weather on an enormous exoplanet 280 light-years from Earth, and the forecast looks grim. The planet, named WASP-43b, is tidally locked, with one massive face always pointing toward its star and the other cloaked in eternal darkness. Significant temperature differences between the two sides drive fierce winds, which scientists estimated to blow at up to 5,600 mph (9,000 km/h) — several times faster than a speeding bullet.

The hellish world with glorious rainbows

The exoplanet WASP-76 b — located about 637 light-years from Earth — is not the type of place you'd want to vacation. Orbiting 20 times closer to its home star than Mercury orbits the sun, the planet's dayside is estimated to reach 4,350 degrees Fahrenheit (2,400 degrees Celsius), making it a true hell world. There is one draw, however: A strange bright spot observed on the planet's surface, right where the day and night sides meet, could be a "glory" — a rare visual phenomenon, sometimes seen on Earth, made up of concentric rainbow rings forming a giant circle.

The giant planets orbiting dead stars

One day, the sun will die — but some planets in our solar system may live on. Scientists made this inference after discovering two enormous planets orbiting "dead" white dwarf stars in distant star systems. Named WD 1202-232 and WD 2105-82, the planets are estimated to be between one and seven times as massive as Jupiter, and both orbit small, dead stars at distances of at least 11.5 times that between Earth and the sun. Their discovery, if confirmed, hints that our solar system's comparable planets, Jupiter and Saturn, may be able to survive the inevitable death of the sun one day. (Earth, sadly, is likely to be swallowed up during our star's final expansion.)

The "rogue" planets of Orion

Most known planets orbit stars, but there may be countless others that don't. Scientists using the JWST have discovered hundreds of free-floating "rogue planets" zooming through the Orion Nebula, untethered to any star. Strangely, about 80 of these rogue worlds are trapped in binary orbits with each other, tumbling through space in pairs. Scientists are not certain how these worlds got ejected from their home star systems or why they are trapped in binary orbits. Given that these planets are roughly as massive as Jupiter, scientists have dubbed them Jupiter-mass binary objects — or JuMBOs, for short.

The distant planet we can actually see

Scientists detect most exoplanets indirectly, by watching changes in the light emitted by distant stars. But in 2004, researchers got direct visual confirmation of an alien world for the first time ever. Called 2M1207b, the exoplanet is located about 170 light-years away, in the constellation Centaurus, and is a gas giant about five times more massive than Jupiter. The team spotted the distant world by looking at it in three different infrared wave bands, which helped reveal the planet's heat while blocking the light of its home star. Since this groundbreaking discovery, roughly 200 exoplanets have been discovered through direct imaging, while more than 5,000 others have been revealed through other means.

The planet with clouds of quartz

Can you imagine a sunset filtered through a crystal sky? That may be a reality on the exoplanet WASP-17b, a Jupiter-like gas giant that's so hot that its clouds are made of quartz crystals, observations with JWST suggest. The planet orbits extremely close to its home star, giving it an atmosphere with temperatures reaching a blistering 2,700 F (1,500 C). This heat forms tiny, sand-size silica particles in the planet's atmosphere, which may coalesce into clouds of pure quartz, researchers suggest.

The baby Jupiter about to be born

Exoplanet-hunting scientists zoom in on not just existing worlds but also worlds that are about to be born. While studying the region around the star V960 Mon, located about 5,000 light-years from Earth, scientists spotted a clumpy field of gas where two tendrils of material are apparently being funneled into distinct, planet-like lumps. According to the researchers, who made the discovery using the European Southern Observatory's Very Large Telescope and the Atacama Large Millimeter/submillimeter Array, this is the first time scientists have imaged a young star system on the verge of birthing its first giant planets.

The sibling planets dancing in lockstep

Around the distant star PDS 70, located 370 light-years from Earth, resides an incredibly rare pair of sibling planets. One fully formed world roughly the size of Jupiter appears to swirl around its host star; behind it, in the same orbit, is an enormous cloud of gas and dust that researchers suspect may be the planet's partially formed sibling. Although only one of the objects seems to be a full-fledged planet, the pair is the first evidence of rare "Trojan planets" — two worlds that formed at nearly the same time, in roughly the same place around their home star, moving in the exact same orbit.

The planet turning its star into a "spiral galaxy"

About 500 million light-years from Earth is a star system that looks suspiciously familiar. Wrapped in two dusty spiral arms, it resembles our own Milky Way galaxy — although on a much, much smaller scale. The reason for this star's galactic appearance? Astronomers suspect it's because of a hidden, Jupiter-size planet dubbed MWC 758 c, which used its massive gravitational pull to sculpt the star's sheath of dust into spectacular spiral arms. The planet has yet to be fully confirmed, but simulations show it's a likely cause of its home star's odd look.

The mirror world that shouldn't exist

Most planets reflect at least a bit of their home star's light. But the exoplanet LTT9779 b reflects a whopping 80% of its star's incoming rays — the highest reflectiveness of any planet ever discovered. The key to the planet's impressive albedo is a layer of metallic clouds that surrounds it. Scientists suspect the Neptune-size world's sky is mostly full of silicate, or glass, and titanate, a salt containing titanium — turning the planet's atmosphere into a veritable mirror. The planet's existence poses a puzzle for scientists: The world orbits so closely to its star that its atmosphere should have been blown away by now. The key to its survival may be the metal in the planet's skies, which may be too heavy for solar wind to blast it away.

The "zombie" planet that survived its star's death

The exoplanet 8 Ursae Minoris b, also known as Halla, is a hot, Jupiter-like world located 520 light-years from Earth. Observations suggest the massive world should have been completely incinerated by its home star, which has already entered its red giant phase and appears to have long since ballooned outward into its system, scorching everything in its path, before shrinking back to its current size. The fact that Halla orbits relatively close to the star suggests it was either born after the star shrank again or the star that's visible today is one of two binary stars that merged, preventing either one from expanding on its path of destruction.

The water world with a steam atmosphere

The exoplanet GJ 1214b is located just 40 light-years from Earth, but it's coated in so many thick clouds that scientists had a hard time studying it until recently. Using JWST's infrared vision to peer through the clouds, scientists analyzed the planet and saw what appeared to be an atmosphere made of steam, suggesting the world below may contain significant amounts of water.

The Earth-like planet with no atmosphere

Around the distant star TRAPPIST-1, seven rocky, Earth-size planets swirl through the star's habitable zone. Whether any of these planets contain the right conditions for life is a question astronomers are eagerly investigating. But one of them, TRAPPIST-1b, may be officially out of the running. JWST's observations of the rocky, Earth-like world reveal that the planet is about as hot as an oven — a whopping 450 F (232 C) — and almost certainly doesn't have an atmosphere. Some of the scorching world's neighbors may be better positioned for life to emerge, but more research is needed to know for sure.

The extraterrestrial sandstorm planet

Scientists using JWST have spotted a gargantuan sandstorm raging on the exoplanet VHS 1256 b, located roughly 40 light-years from Earth. An enormous world that's far from its star, the "super-Jupiter" takes about 10,000 years to complete a single orbit. That large distance means scientists can see the planet's atmosphere relatively clearly, without too much starlight getting in the way. Recent observations showed incredibly hot clouds made of silicate particles swirling through the planet's atmosphere. According to the researchers, this may be evidence of a gargantuan dust storm.

The planet hotter than a star

KELT-9b is an extremely hot, Jupiter-like planet located 670 light-years from Earth. With an estimated surface temperature of 7,800 F (4,300 C), it was deemed the hottest exoplanet ever discovered upon its detection and is even hotter than some stars. This intense heat has a nasty impact on the planet's atmosphere: On KELT-9b's dayside, the heat of the nearby star beats down so intensely that hydrogen molecules in KELT-9b's atmosphere are literally ripped to shreds and blown across the planet. With one-half of the planet's atmosphere constantly melting, this world is one extraterrestrial destination you'd definitely want to avoid.

The toxic football planet

Located about 900 light-years from Earth, the exoplanet WASP-121b is so hot that heavy metals are constantly boiling through its atmosphere and venting into space. Scientists spotted iron and magnesium molecules so high above the planet's surface that they could escape the pull of gravity and drift away. The extreme heat comes from the planet's ultraclose proximity to its host star. The planet is so close, in fact, that tidal forces generated by the star's gravity have stretched the planet into a football shape that distinguishes it from the spherical worlds most often discovered.

The ultrasmall world moving at breakneck speed

Located 35 light-years from Earth, L 98-59b is one of the smallest exoplanets ever discovered, with a mass just 0.4 times that of Earth. The tiny world also rockets around its home star at breakneck speed, completing an orbit in just two days, six hours. Because of this, the planet receives roughly 22 times as much energy from its home star as Earth does from the sun, almost certainly rendering the tiny, fast-moving planet uninhabitable.

Earth's "older cousin"

The exoplanet Kepler-452 b appears so similar to our home planet that NASA has dubbed the world "Earth's older cousin." The rocky exoplanet orbits a sunlike star at virtually the same distance that our planet orbits the sun, with a year there lasting about 384 days. That puts the planet firmly in the habitable zone, where liquid water could form on its surface. Sadly, our cousin will remain estranged for a good while longer: At nearly 1,800 light-years from Earth, the planet would take at least 30 million years to reach by spacecraft.

The bizarrely close sibling planets

The exoplanet Kepler-36b is a rocky world that's about 1.5 times the size of Earth and orbits bizarrely close to its neighboring world, the Neptune-like exoplanet Kepler-36c. The two alien worlds make extremely close approaches to each other every 97 days, on average; during those cosmic family reunions, the two planets are separated by less than five Earth-moon distances. These ultraclose encounters exert tremendous tidal forces on the sibling planets, possibly promoting active volcanism on the rocky Kepler-36b.

The unlucky planet around a toddler star

The exoplanet AU Microscopii b, located about 32 light-years from Earth, is unlucky enough to have formed a scant 6 million miles (9.6 million km) from its host star — an extremely young, hot, temperamental red dwarf. Estimated to be just 23 million years old, the star is a mere toddler in cosmic terms. (The sun, by comparison, is 4.6 billion years old.) The young star routinely erupts with blasts of radiation thousands of times stronger than the worst solar flares the sun can spit out — and poor AU Microscopii b is often in the firing line. Astronomers have noticed huge globs of planetary material orbiting near the distant world, suggesting that the temperamental star is blasting away pieces of the planet's atmosphere bit by bit.

In the fight against climate change scientists have invented some weird and wonderful ways to cut greenhouse gases, stop glacier melt and shade the powerful rays of the sun to reduce the planet's surface temperature. The future of Earth relies on humankind's ability to curb our reliance on fossil fuels — and ultimately use fewer natural resources.

Here are 32 of the weirdest ways scientists have suggested to combat climate change.

Artificial volcanoes

To slow global warming, scientists have proposed creating artificial volcanoes to form an enormous "heat shield" that reduces Earth’s temperature. The "Pinatubo strategy" involves launching jets into the stratosphere that release sulfur compounds, which reflect sunlight away from the Earth — mimicking the natural impact on the atmosphere as a volcanic eruption. 

In 2011, as part of the three-year Stratospheric Particle Injection for Climate Engineering (SPICE) project, scientists from the U.K. used a giant pipe and balloon in a field experiment that injected particles into the stratosphere to generate cooling.

Wrap Greenland in a reflective blanket

Scientists have explored wrapping Greenland in a massive, reflective blanket to slow the rate of glacier melt. In 2009, climate scientist Ken Caldeira at the Carnegie Institution for Science suggested that reflecting sunlight away from various regions — mostly in the Arctic — could reduce the warming effect and glacier melt. 

In the Discovery series "Ways To Save The Planet" which aired in 2009, scientists led by glaciologist Jason Box use reflective, white polypropylene blankets to cover glaciers and test the theory.

Feed livestock garlic

Livestock is the world's largest producer of methane — a hazardous greenhouse gas that contributes to global warming and more than 1 million premature human deaths annually. Reducing agriculture-related methane emissions, which are caused by the release of gas by farting and burping, is key to fighting climate change, according to a report by the United Nations Environment Programme (UNEP) and Climate and Clean Air Coalition. 

Scientists have found that feeding livestock garlic, which contains bioactive organosulfur compounds, cuts methane emissions and produces health benefits for consumers of meat and dairy products from the livestock.

Artificial trees that remove CO2 from the air

Planting forests of artificial trees that contain layers of carbon dioxide-absorbing discs could fight climate change on a global scale, according to scientists from Arizona State University (ASU). The mechanical trees use carbon-capture technology, and can reportedly capture CO2 a thousand times quicker than natural trees. Developed by Klaus Lackner, physicist and director of Center of Negative Carbon Emissions, the first mechanical tree was installed on the ASU campus in 2022.

Force-feed plankton blooms

Phytoplankton, a microscopic plant that floats in the ocean, provides food for marine life, produces oxygen, absorbs carbon dioxide and releases oxygen into the air. Pollution from agriculture and industry can cause huge blooms of plankton to form. Scientists hope that by fertilizing the deep ocean with iron, they can cause huge swathes of plankton to bloom and absorb extra CO2. This method was reported by The Times in 2019 but remains a controversial approach to fighting climate change.

Fake whale poop

Scientists want to increase the volume of greenhouse gas emissions that the ocean captures by creating artificial whale feces using iron-rich sand or volcanic ash. Whales naturally defecate iron-rich poop on the ocean’s surface that causes huge blooms of phytoplankton to form, which feed fish and capture carbon. 

Professor Sir David King, chair of Cambridge University's Centre for Climate Repair and lead of the fake excrement project, hopes that these plankton blooms could capture 50% of the world's greenhouse gas emissions.

Giant snow cannons to blast glaciers

Live Science previously reported an unusual solution to prevent Antarctica’s western ice sheet from collapsing: massive snow cannons. These cannons pump seawater to create trillions of tons of artificial snow to blast across glaciers. 

According to a 2019 study published in the journal Science, creating an artificial blizzard in the coastal area around Thwaites and Pine Island glaciers could stabilize the West Antarctic Ice Sheet , reducing ice loss and significant sea level rise. Anders Levermann, physicist at the Potsdam Institute for Climate Impact Research and study co-author, said in a statement: "The West Antarctic Ice Sheet is one of the tipping elements in our climate system. Ice loss is accelerating and might not stop until the West Antarctic ice sheet is practically gone."

Use drones to plant tree bombs

Planting forests from the sky using drones has been explored as a solution against deforestation after wildfires and in areas that are difficult to reach. In Australia, AirSeed Technologies is using drones and AI to drop "seed bombs" in areas devastated by bushfires or flooding.. 

According to the U.N.’s Intergovernmental Panel on Climate Change, reforestation is vital to reduce the effects of climate change. A 2019 study found that there is space on Earth to plant hundreds of billions of trees, with the potential to reduce atmospheric carbon levels by 25%. According to a 2020 study, replanting trees could reduce the U.S. carbon footprint by 14%.

Lab-grown meat

Eating lab-grown cultivated meat rather than livestock-reared beef was previously thought to be better for the environment. Lab-grown meat doesn't require pastures for grazing, uses less water and land for growing feed and produces less methane than cattle. 

However, a 2023 study found that the energy needed and greenhouse gases emitted at all stages of cultivated meat production is between four and 25 times higher than traditional beef-rearing. This echoes the findings of a 2019 study that suggested that although cattle contribute to global warming by emitting methane, overall cultivated meat could be worse for the planet in the long-term. 

Although scientists haven't yet found a low-emission solution to cultivating lab grown meat, from an animal-welfare perspective cultivated meat still has a positive impact.

Eat a plant-based diet

In a 2024 report, scientists found that in order to reduce greenhouse gases and global heating by 1.5 degrees Celsius, people need to consume fewer meat and animal products and switch to a mostly plant-based diet. 

This echoes an earlier 2020 report that found evidence that reducing meat consumption significantly and switching to a plant-based diet is the ultimate solution to reduce global emissions. 

A separate 2021 report found that animal-based foods emit twice the amount of global greenhouse gas emissions as plant-based foods.

Plastic-eating enzymes

Humans are generating twice as much plastic as we did just two decades ago, with just 9%of plastic successfully recycled. Plastic isn’t biodegradable and can take up to 500 years to decompose, according to the United Nations. 

Figures from the University of Colorado show that the refinement of plastics emits 184 to 213 million metric tons of greenhouse gases each year. The disposal of single-use plastics in landfills accounts for more than 15% of methane emissions. 

In 2022 Live Science reported that an AI-engineered plastic-eating bacteria had been developed that could solve the plastic problem. Researchers found a variant of an enzyme called hydrolase that can break down PET (polyethylene terephthalate) into component molecules. A separate 2023 study found evidence that structural biology could be used to develop an enzyme that "'eats" plastic.

Build cloud-making ships

Scientists have explored installing a fleet of "cloud-making" ships to increase cloud cover and cool the atmosphere. The technique, "marine cloud brightening" (MCB), involves finding the aerosol particle size that is "just right." 

"Since there is a risk that particle size can either increase precipitation or increase evaporation, the optimal particle size and number will likely need to be matched to the target cloud," NOAA scientist Graham Feingold said in a statement. 

According to a 2021 study, stratocumulus decks, which cover large areas of Earth’s surface, would be the primary target.

Build underwater walls to protect glaciers

Walls made of rock and sand on the seafloor could be used to protect undersea glaciers from melting and reduce the risk of sea levels rising in Antarctica, according to researchers. 

In a 2018 study, researchers explored this form of geoengineering to mitigate the impact of climate change on coastal areas. The structures would be used to stop warmer water from reaching the base of the glaciers, a leading cause of glacier melt. The Guardian reported that the base of the ice around the South Pole shrank by 556 square miles (1,463 square kilometers) between 2010 and 2016.

Dim the sun

Although dimming the sun wouldn't reverse climate change, it could create a cooling effect, researchers have found. According to a 2018 report, a solar engineering technique that reflects some of the sun's rays into space could help limit the rise in global temperatures to less than 1.5 degrees Celsius and meet targets set in the Paris Agreement. 

According to a 2023 study, using a combination of solar engineering techniques to block some sunshine could also protect polar regions from melting.

Spray arctic ice with glass

Summer Arctic sea ice is shrinking at a rate of 12.2% per decade, compared to its average extent during the period from 1981 to 2010, satellite observations from NASA show. 

One solution could be to coat large swathes of the Arctic in a thin layer of reflective glass beads that protect young ice and allow older ice to form, according to the Arctic Ice Project, a nonprofit organization. Research experiments to test the geoengineering technique in lakes and rivers in Canada have demonstrated some successful results, according to a 2018 study.

Paint buildings white

Painting buildings in an ultra-cooling white paint could provide an affordable cooling solution, researchers have found. In many hot countries, such as Greece and Spain, white houses are the norm. They reflect the sun's powerful rays, making the buildings cooler. 

In 2023, researchers invented a new ultra-white formula that modeling experiments found reflects 98.1% of solar heat away from the surface. The paint gained an Innovation Award for its potential to keep surfaces cool and reduce the need for air conditioning.

Recycle human waste

Researchers have found that composting human waste to use as a fertilizer for agriculture reduces greenhouse gas emissions and waste-borne illnesses. 

A 2020 study published in Nature investigated the sanitation and composting of human waste at large slums in Haiti, where only 30% of the population has access to sewer sanitation. Researchers found that off-site composting had a methane emissions factor of 0.5%, compared to 20 to 80%from pit latrines and lagoons.

"Composting has a much smaller greenhouse gas footprint than all of the other non-sewer technologies that are used widely today," University of California, Merced Professor Rebecca Ryals and study co-author said in a statement.

Eat insects

Insects could provide an alternative source of protein and reduce greenhouse emissions, according to the World Economic Forum. A 2017 study reported that cricket farms emit 75% less carbon dioxide and half as much water as poultry farms. 

Separate research from 2023 found evidence that edible insects, many of which are regarded as pests, could solve many environmental and health issues by reducing greenhouse gases emitted during food production and providing an additional food source as the global population continues to grow.

Use algae for food, fuel and cement

Scientists researching the potential uses of microalgae for carbon capture and in medications and foods found that some species of algae form limestone, which can be used to make biocement and reduce carbon use. 

A 2024 study found evidence microalgae could be used as a biofuel and a greener solution to fossil fuels. A separate 2024 report found that algae is increasingly added as a nutritious ingredient in plant-based food. Compared to conventional plant and animal sources, the researchers found that algae used fewer natural resources to grow and harvest.

Use the human body as an energy source

Rather than cooling the heat produced by humans in busy urban areas, scientists are using human heat to warm buildings. 

In Sweden, an eco-office building situated above Stockholm Central Station recovers the excess body heat produced by thousands of commuters.. Using heat exchangers, the excess heat is converted to warm water, which supplies up to 20% of the office heating. To cool the building, water is extracted from a nearby lake.

Use asbestos to remove CO2 from the air

Scientists are exploring how asbestos (in its natural form) could be used as a "carbon sink" to remove CO2 from the atmosphere. Asbestos is a naturally-occurring fibrous silicate mineral that is harmless in the soil, but when manufactured, it becomes a carcinogenic compound that causes serious health problems when breathed in. 

In a 2019 study, scientists reported how the waste from mining, including asbestos, could be used to capture carbon.

Paint mountains white

In 2010, a Peruvian inventor whitewashed a mountain summit in the Peruvian Andes in an experiment to see if it could protect against glacier melt by reflecting heat away from the peaks. The Glaciares de Peru Project's early example of geoengineering won a $200,000 prize as part of the World Bank's "100 Ideas to Save the Planet" competition. 

In 2023, Reuters reported that 56% of Peru's tropical glaciers had disappeared in the last six decades as a result of climate change.

Grow more sea ice in the Arctic

In 2023, researchers from the Centre for Climate Repair at the University of Cambridge undertook an experiment in Cambridge Bay in the Arctic Circle to drill and pump seawater across the surface to freeze and therefore thicken the ice. 

This, the team said, could protect it from melting and restore lost ice to mitigate some of the effects of carbon emissions. The 2024 study examining the impact of the experiment found evidence of freezing further away from the point of injection, suggesting thickening ice in the Arctic could be a helpful strategy to mitigate further ice loss.

Live in trash houses

The construction industry is responsible for a large proportion of global carbon emissions and it sends a huge amount of waste to landfills each year. The European Commission estimates the industry produces over a third of the European Union's waste. Approximately half of the 100 billion tons of raw materials extracted across the globe annually are used in construction. 

One solution being tested is using recycling materials such as plastic to create bricks. A 2022 study reported that the use of recycled building materials, such as plastic, glass, concrete and steel, during construction could reduce the environmental impact caused by construction by up to 65%.

Bury carbon underground

Capturing and storing carbon, a process known as carbon sequestration, can reduce carbon dioxide in the atmosphere and lessen its impact on the environment. 

In a 2022 study, researchers investigated the importance of erosion in carbon burial to see if subsoil could be used with "frontier" technologies to store greater quantities of carbon. Scientists found evidence to indicate that subsoil could be used to capture carbon with large quantities of carbon recorded in centuries old subsoil.

Space-based solar power

Since the 1920s, scientists have been exploring how space-based solar power can be harvested and transmitted back to Earth.

According to NASA, large orbital solar panels could be blasted into space, and the energy they collect then sent back to our planet using laser or microwave beams. A 2024 report by NASA evaluated the potential cost and conditions needed to deliver space-based solar power and the role NASA could play in developing technologies to harness this energy.

According to the European Space Agency, sunlight is 10 times more intense in the atmosphere than it is on Earth’s surface, and space-based solar power could aid in Europe achieving a net-zero greenhouse gas emission target by 2050.

Fly less

Traveling by plane contributes significantly to climate change. The aviation industry generates up to 2.4% of global carbon emissions annually, according to a report published in the Atmospheric Environment Journal. The Environment and Energy Study Institute reported that the "hypermobility" of air travel caused the annual global passenger count to reach 4.56 billion people in 2019. In a 2022 study, researchers investigated how behavioral changes, such as abstaining from flying, choosing an alternative means of transport and carbon offsetting, could be encouraged to reduce individual impact.

Grow algae in the ocean to reduce acidity

The ocean absorbs around a third of the planet's carbon dioxide from the atmosphere. However, as carbon dioxide emissions have increased, scientists have found that seawater has become more acidic, and less effective at carbon capture. 

But algae can help "calcify" the water by releasing enzymes that break down carbon dioxide into bicarbonate ions. These ions can then be used for calcification. In a 2016 study, scientists found that algae helps the water stay neutral and absorb more carbon.

Reintroduce woolly mammoths

In a project reminiscent of Jurassic Park, scientists from Harvard University have explored bringing woolly mammoths back to life.

According to researchers from the Woolly Mammoth Revival Project, reintroducing previously extinct large animals and herbivores to Arctic environments could reduce greenhouse gases by acting as a natural geoengineer. By trampling around, they could help grasslands — which absorb less heat than trees — to thrive, while preventing permafrost to thaw.

Train cattle to use the loo

Researchers from New Zealand have successfully "potty trained" cattle to use a toilet, nicknamed a "MooLoo."

The projects aims to reduce ammonia emissions from urine and dung from leaching into the soil and nearby water sources, causing nitrous oxide — a type of greenhouses gas — and acid rain. 

According to the 2021 report, a single cow can produce 30 liters of urine daily. Ammonia is produced when this urine combines with feces. Although urine isn't as damaging as the methane produced by farting and burping cattle, the nitrous oxide from urine was found to make up 5% of all greenhouse gases from agriculture in the U.K. in 2019.

Build wind farms in the sky

Airborne technology could be a solution in the fight against climate change. These technologies, such as huge kites, are being explored as a method for harvesting wind power high above the ground and in remote locations where conventional wind turbines can't be installed.

According to a 2013 study, high-altitude winds are generally more powerful than near-surface winds, resulting in up to 4.5 times higher average power densities.

Use nature to encourage people to care about the planet

The United Nations has outlined 10 actions that people can take to reduce their carbon footprint and save the planet. These include using less energy, consuming fewer products generally (such as clothing, electronics), recycling more and using greener modes of travel.

According to a 2023 study conducted by researchers at the University of Tokyo, people who spend more time in nature are more likely to care about the natural environment and take action to protect it. Researchers found evidence that giving people a chance to experience nature boosts empathy for the health of the planet and encourages prosocial behavior.

Measuring animal intelligence is tricky. As humans, we can only compare the smarts of other creatures with our own — an inherently biased benchmark.

"Asking which species is smarter is like asking if a hammer is a better tool than a screwdriver," Brian Hare, founder and director of Duke University's Canine Cognition Center, told PBS in 2018. "Each tool is designed for a specific problem, so of course it depends on the problem we are trying to solve."

Scientists don't have a standard definition or test for "intelligence." Some look at tool use, brain-to-body ratios, brain sizes, problem-solving abilities or self-awareness, but whether these measures really capture animal intellect is debatable.

Still, some animals show remarkable cognitive abilities that sometimes rival our own. Here are 32 of the smartest animals on the planet.

Chimpanzees

Chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) are Homo sapiens' closest relatives. Both share almost 99% of our DNA and are widely considered some of the brightest creatures in the animal kingdom.

In 1960, chimps became the first nonhuman animals to be documented using tools — an ability scientists previously thought was unique to humans. Further research has uncovered complex social lives, a range of human-like emotions and metacognition, or the ability to "think about thinking." In certain brain and memory games, scientists discovered that chimpanzees actually outperform humans, according to a study published in the journal Nature in 2014.

Researchers have even taught chimpanzees to use American Sign Language. Washoe, the first nonhuman primate to learn to sign, learned 350 signs before she died in 2007. Her adoptive son, Loulis, learned about 50 signs entirely from Washoe and other signing chimps. Subsequent research challenged whether chimpanzees can actually combine words to create new ideas or whether they simply memorize signs.

Dolphins

Dolphins are so smart that many consider them the second-most-intelligent creatures on Earth. These cetaceans have complex social lives, understand abstract concepts, use tools, solve problems, show sophisticated emotions and have an incredibly high brain-to-body ratio (about the same as Homo habilis, an archaic human species). Studies have also shown that bottlenose dolphins (Tursiops truncatus) can recognize themselves in a mirror and may be capable of metacognition.

Like dogs, dolphins can learn commands from humans. These creatures are so good at communicating with us that back in the 1960s, researchers believed we might even learn to "speak" to them by giving them LSD. While these tests failed, researchers have continued attempting to decode dolphin clicks and whistles. In 2013, scientists discovered that dolphins identify each other by unique names and that they can remember these names for at least two decades.

The U.S. Navy has trained both dolphins and sea lions to detect trespassers in forbidden areas like piers, harbors and ship channels. Dolphins have also been used to detect unexploded underwater mines.

Bonobos

Like their chimpanzee cousins, bonobos (Pan paniscus) have incredible mental prowess. Some researchers think these primates, along with chimps and orangutans, have a cognitive ability known as "theory of mind." Creatures with theory of mind understand that other beings think differently and have different beliefs and desires.

Bonobos are good problem-solvers and adept at solving tasks that require an understanding of social causality. Research has suggested that bonobos and chimpanzees can remember familiar faces after at least 26 years of separation.

Unlike chimps and humans, bonobos have never been documented killing each other. Male bonobos engage in frequent squabbling, but their fighting is usually less intense than that of their great ape relatives. Research has suggested that bonobos are tolerant of outsiders, will readily share food (but not toys or tools) and solve conflicts through sex.

Sperm whales

The sperm whale (Physeter macrocephalus) has the biggest brain of any animal on Earth today, with an average weight of 17 pounds (7.8 kilograms). Though scientists have long argued whether brain size — and even brain-to-body ratio — is a good indicator of high intelligence, many agree that sperm whales are some of the smartest creatures in the ocean.

Sperm whales form tight-knit family groups with distinct cultures. To communicate with one another, the whales produce patterns of clicks called codas. These codas differ from group to group, similar to dialects in human language. Sperm whales excel at learning from one another. In the 19th century, they were prime targets for whalers, but research suggests these creatures taught each other how to avoid attacks.

Pigeons

Pigeons aren't as "bird-brained" as they may appear. They can count, recognize words, and have an impressive memory and excellent vision. Pigeons can also differentiate categories of objects. In 2015, scientists taught pigeons to sort 128 images into 16 categories. When presented with new images from the categories, the pigeons could still sort them correctly. Pigeons can also recognize themselves in a mirror.

In an unusual study in 1995, researchers taught pigeons to discriminate between the artwork of Monet and Picasso. After some training, the birds were presented with a new-to-them piece of art and were able to determine which artist had painted it. The pigeons were then further trained to distinguish between Monet, Cezanne and Renoir pieces and then between Picasso, Braque and Matisse paintings. And in a 2015 study, researchers discovered that pigeons could be trained to detect cancer in breast pathology images.

During World War II, before guidance technology systems were created to aim missiles, experimental psychologist B.F. Skinner taught pigeons to accurately guide missiles to a target. The system, known as "Project Pigeon," proved incredibly successful, but it was shut down before it could be put to use.

Elephants

Elephants have the largest brains of any land animal. These giants have extraordinary memory, high social intelligence, excellent problem-solving abilities and complex emotions.

In a 2014 study published in the journal PNAS, researchers discovered that African elephants (Loxodonta africana) could identify the voices of the most threatening humans based on their ethnicity, gender and age.

Elephants are widely recognized as some of the world's most empathic creatures. They live in tight-knit family groups and have been recorded helping each other in distress and grieving for their dead. Elephants use tools and complete tasks, and they even understand when their own bodies hinder them from solving problems. Like the mirror test, which elephants have also passed, this may be an indication of self-understanding, some researchers say.

Octopuses

Researchers think common octopuses have an impressive 500 million neurons in their nervous systems — about as many as a dog. They have the largest brain-to-body ratio of any invertebrate. These cephalopods have a reputation for being exceptionally talented escape artists and puzzle solvers. They can unscrew jars from the inside, untie knots, use tools, recognize individual humans and play pranks. When hunting, California two-spot octopuses (Octopus bimaculoides) can be quite calculated; their arms work together in specific, choreographed motions that differ depending on which animals they're going after.

While octopuses are more genetically similar to other mollusks, like squid and cuttlefish, than to humans, we do have some genetic similarities. Both humans and octopuses have an abundance of "jumping genes" — DNA sequences that move from one location in the genome to another. Interestingly, octopuses have more protein-encoding genes than humans do — over 33,000, compared with our 20,500.

Rats

Rats get a bad rap, especially in densely populated cities. These creatures are so reviled that, in 2023, New York City Mayor Eric Adams appointed the city's first-ever "rat czar" to eliminate the rodents. While it's true that rats can transmit pathogens — including hantavirus; Rickettsia typhi (which causes murine typhus); Spirillum minus and Streptobacillus moniliformis (which cause rat-bite fever); and Salmonella — to humans, rats are actually clean, intelligent creatures. They groom even "more frequently and thoroughly than cats," Dr. Jennifer Graham, a veterinarian at the Henry and Lois Foster Hospital for Small Animals, said in a 2020 interview.

Rats can learn tricks, solve puzzles, feel empathy, rescue friends in need and even have an imagination. In a 2014 test of rat learning and cognition, researchers found that rats can even outperform humans in implicit category-based generalization, or the ability to apply certain learned patterns to new sets of information. Research published in the journal Current Biology in 2007 suggested that rats may be among the few nonprimates capable of metacognition.

Orangutans

All great apes have advanced mental capabilities, and orangutans (Pongo) are no exception. These apes are excellent learners; an orangutan named Chantek became one of the first apes to learn sign language, and he even invented signs of his own. Chantek was raised by an anthropologist and learned to clean his room, use the toilet, play games and paint.

A 2018 study in the journal Science suggested that orangutans are capable of "displaced reference" — the ability to reference things not happening in the present. In their study, researchers disguised themselves as big-cat predators and watched how orangutan mothers with young would respond. The scientists reported that after spotting a predator, the orangutan mothers ushered their young to safety but waited to sound the alarm until after the danger had passed.

"There was no reason for orangutan females to vocalize after a predator model was removed, but they did so nonetheless," researchers wrote. They hypothesized that the orangutans were teaching their young that they had been in danger. "Postponing behavior in time and space inherently expresses a role of high cognitive processing of the stimulus and general intelligence," the researchers said.

Crows