Astronomers have found the strongest evidence yet that a rocky planet beyond our solar system has managed to hold onto an atmosphere — a crucial ingredient for life as we know it.

The discovery marks the first time scientists have detected an atmosphere surrounding a rocky planet orbiting in the habitable zone of another star, the region around a star where temperatures could enable liquid water to exist on a planet's surface. The findings, published July 16 in the journal Science, could help astronomers narrow the search for potentially habitable worlds beyond our cosmic backyard.

"It's absolutely exciting," Edward Schwieterman, associate professor of astrobiology at the University of California, Riverside, who was not involved in the study, told Live Science in an email. "We are getting closer to studying the atmospheres of worlds that could plausibly harbor life, with evidence of that life embedded in their observable spectra."

The planet, known as LHS 1140 b, lies about 48 light-years away from Earth and orbits a small, cool red dwarf star. At roughly 5.6 times Earth's mass, the exoplanet is classified as a super-Earth: a rocky planet larger than our own but much smaller than gas giants like Neptune.

It receives less than half the sunlight Earth gets, giving it an estimated surface temperature of around minus 53 degrees Fahrenheit (minus 47 degrees Celsius), according to previous estimates not accounting for an atmosphere. That makes the planet cold, but in the range astronomers consider potentially habitable.

Cosmic gas leak

Scientists have discovered thousands of exoplanets over the past few decades, including many rocky worlds. But determining whether those planets have atmospheres has proven far more difficult, because atmospheres around rocky planets are incredibly thin compared with those of giant planets, making them much harder to detect across vast cosmic distances.

Instead of looking for the atmosphere directly, the researchers behind the new study searched for a subtle clue that one existed: helium gas leaking into space. Using the WINERED spectrograph on the Magellan Clay Telescope in Chile, the team watched LHS 1140 b cross in front of its star and let a sliver of starlight filter through the planet's atmosphere on its way to Earth. As it did, the team looked for a tiny dip in the star’s light at the exact wavelength of infrared light that helium blocks — a telltale sign that gas was streaming off the planet and into space.

The prediction rested entirely on a mathematical model that had never been confirmed for a rocky planet. However, in September 2024, the team caught LHS 1140 b and a smaller, hotter neighboring planet, LHS 1140 c, transiting their star on the same night, less than 40 minutes apart. The researchers detected a clear helium signal from LHS 1140 b, while LHS 1140 c showed nothing.

The contrast matters: LHS 1140 c orbits much closer to its star than LHS 1140 b does and receives roughly five times the radiation, yet it's also smaller and less gravitationally bound — conditions that should make any escaping gas easier, not harder, to spot. Finding nothing there suggests LHS 1140 c's atmosphere was stripped away long ago, while LHS 1140 b, sitting farther out in cooler, calmer conditions, has managed to hold onto its own.

The discovery addresses a question astronomers have been working to answer for decades.

"Twenty years ago we wondered whether other terrestrial-type planets even existed," study co-author Robin Wordsworth, a professor of Earth and planetary sciences at Harvard, said in a statement. "Then we learned they're common, and found some in the habitable zone. The next question was whether any of them had managed to keep an atmosphere. Now we know at least one has."

A step forward in the hunt for life

The find is especially notable because red dwarf stars like LHS 1140 can bombard nearby planets with high-energy radiation capable of stripping atmospheres away over time. Based on the star's estimated age of at least 3.1 billion years, the researchers say LHS 1140 b's atmosphere has likely persisted despite that bombardment, suggesting some rocky planets around these common stars can hang onto their atmospheres for far longer than once assumed.

But the researchers caution that detecting helium does not mean the planet is inhabited — or even that it is habitable. The observations reveal only the planet's thin upper atmosphere, not its full composition. Scientists still don't know whether LHS 1140 b has oxygen, carbon dioxide, water vapor or other gases that could make its surface more Earth-like and hospitable to life.

Instead, the discovery opens a new way to study distant rocky worlds.

"The study demonstrates that, at least in some cases, we will be able to begin characterizing the atmospheres of potentially habitable planets," Schwieterman said. "If only rocky planets orbiting Sun-like stars retained atmospheres, we might have to wait one to two decades for the launch of the Habitable Worlds Observatory to search for biosignatures on rocky planets. I'm certainly excited about what comes next!"

Future observations will aim to determine what the rest of LHS 1140 b's atmosphere is made of and investigate whether it may harbor oceans or other features associated with habitability.

A hefty "super Earth" lurking in one of the closest star systems to our planet may be much better suited to supporting extraterrestrial life than scientists initially thought, a new study suggests. The alien world's relative proximity to Earth, and the nature of its home star, make it a prime candidate for follow-up observations, researchers say.

The exoplanet, dubbed GJ 3378b, was discovered in 2024 and orbits a red dwarf star around 25 light-years from our planet. The alien world circles its star every 21.5 days at a distance around 10 times closer than Earth orbits the sun, which would make it completely inhospitable in our solar system. But because the red dwarf emits around 90% less radiation than the sun does, GJ 3378b is slap bang in the middle of this star system’s "habitable zone," where liquid water could exist on the exoplanet's surface.

Researchers initially thought that GJ 3378b was around five times more massive than Earth. If the planet is rocky like ours, it would qualify as a "super Earth" — often considered the best candidates for sustaining extraterrestrial life. However, it was hard to tell if this world had a solid surface or was actually a mini gas giant. And even if it was rocky, its immense size would probably mean that its atmospheric pressure would be crushing, making it less likely to harbor life.

But in a new study, published June 30 in The Astrophysical Journal, researchers recalculated the exoplanet's size, using the Habitable-zone Planet Finder instrument attached to the Hobby-Eberly Telescope at the McDonald Observatory in Texas. This device measures subtle wobbles in the host star, caused by the gravitational tug of orbiting planets, and can be used to calculate the planet’s mass and trajectory.

This revealed that GJ 3378b is actually only 2.3 times more massive than Earth, which almost guarantees it is a rocky world and means it could have an atmosphere with a similar pressure to our own, raising the chances that extraterrestrial lifeforms could thrive there.

While researchers have found several other exoplanets that could harbor life, the fact that GJ 3378b is so close to us makes it particularly intriguing, as it will be easier to confirm whether it is truly habitable.

"This one’s exciting," study first author Paul Robertson, an astronomer at the University of California, Irvine, said in a statement. "25 light-years sounds like a long way, but the Milky Way is about 100,000 light-years across, so in that respect it’s our next-door neighbor."

Before we get too carried away, there is still no evidence that GJ 3378b has an atmosphere or liquid water. Its proximity to its home star may mean that any atmosphere it once had was stripped away by stellar winds, similar to how solar radiation likely stripped Mars of its atmosphere and ancient oceans.

Therefore, more observations are needed. But if an atmosphere is detected, GJ 3378b would likely jump to near the front of the queue of exoplanets that researchers want to study further.

"If a planet in the habitable zone has a proper atmosphere, we can justify further research looking for biosignatures, liquid water or other signs of life," study co-author Gogod James, an undergraduate student at UC Irvine, said in the statement.

The fact that GJ 3378b orbits a red dwarf also makes it more appealing for future study because this is the most common star type in the Milky Way, so experts are keen to learn more about these stars' planetary systems and potential to nurture life.

"About 70% of stars in our galaxy are red dwarfs, so they represent the standard," study co-author Michael Endl, an astronomer at the McDonald Observatory and the University of Texas at Austin, said in another statement. "It’s really important that we understand the planet population around these stars."

Researchers have found a new puzzle piece in Mars' geological history that hints that the Red Planet may have once harbored life. New data from NASA's Perseverance rover indicates that mudstones in Jezero crater contain a complex form of carbon, the chemical foundation of all known life. It's the highest concentration of organic molecules found on Mars to date.

Although the mere presence of carbon isn't proof that life once evolved on Mars, the location of the discovery adds to the excitement. This "macromolecular carbon" was discovered near other potential signs of life, or biosignatures, touted by NASA with great fanfare in 2025. This geological context adds credence to the case that microbes may have once colonized the Martian surface. The results were published Wednesday (June 24) in the journal Science Advances.

Perseverance landed in Jezero crater on Feb. 18, 2021. Since then, the site has emerged as one of the most geologically interesting places on Mars. "Jezero crater was once fed water and sediment from rivers, and, billions of years ago, it hosted a lake," Ashley Murphy, a researcher at the Planetary Science Institute and co-author of the new study, told Live Science in an email.

It may have hosted more than that. A study published last year in the journal Nature found that some of the stones in an area of Jezero known as the Bright Angel outcropping contain clays and other minerals that are known to preserve fossils on Earth. One sample, in particular, raised eyebrows: a piece of a rock nicknamed Cheyava Falls, whose patterns resemble those left by terrestrial microbes. Although these patterns could have been created by nonliving sources, NASA officials proclaimed it one of the clearest signs yet of past microbial life on the Red Planet.

The backbone of life

The new research builds on this work by confirming the widespread presence of complex carbon molecules in and around the Bright Angel outcrop. In the study, the researchers used the rover's Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) instrument to map the carbon distribution in these rocks and sediments. They compared them with carbon data from NASA's Curiosity rover taken at Gale crater some 2,300 miles (3,700 kilometers) away, a distribution that suggests water may have been widespread on Mars in the deep past.

Murphy's team also determined that the carbon was not too weathered, indicating that it may have been exposed recently. However, it’s impossible to say whether the newly discovered carbon is related to life or not.

The work is an important step in unraveling Mars' geological history, including the planet's potential habitability and how water shaped its surface. But Murphy cautioned that it is far from a definitive answer.

"Macromolecular carbon on Mars does not prove the existence of life there," Murphy said. The molecules could indicate the presence of fossilized microbes, but they also could have formed through nonbiological means, like meteor strikes or running water.

Until scientists get their hands on a sample directly, it will be hard to tell exactly how this complex carbon arose and whether it represents a true biosignature. But that research may now be decades away — if it happens at all.

The Cheyava Falls sample was originally supposed to be brought to Earth in the 2030s as part of NASA and the European Space Agency's joint Mars Sample Return program. However, in its 2026 budget proposal, the Trump administration deemed the mission "financially unsustainable" and proposed slashing the project. Currently, the project is considered dead.

It may be China that gets the first shot at bringing Martian samples back to Earth for analysis. The country's Tianwen-3 sample-return mission will aim to collect several samples — albeit in a more accessible but less-promising site than where Perseverance has looked for biosignatures — in a mission due to launch no sooner than 2028.

What do you know about the Red Planet? Test your knowledge with our Mars quiz!

Something doesn’t quite add up about the orbits of our solar system’s eight planets and their hundreds of moons, a new study hints.

According to the research — which compared more than 100 simulations of our cosmic neighborhood’s early history — there may have once been two extra giant planets careening around the outer solar system, helping to reshape the orbits of the other planets before ultimately being kicked out into interstellar space.

The infant solar system was constantly being reshuffled. One drastic rearrangement, called the giant planet instability, may have caused the giant planets — Jupiter, Saturn, Uranus and Neptune — to migrate from their initial positions, ending up farther from the sun.

This migration, first proposed in 2005 by astronomers in Nice, France, as a part of the "Nice Model," likely started due to extra-close encounters between the planets and leftover planetary building blocks called planetesimals. Additionally, modifications proposed in 2011 suggested there may have been a fifth giant planet whose gravitational encounters with its neighbors ultimately tossed it out of our cosmic neighborhood.

However, astronomers don't know much about this missing planet. To find out more, the new study "systematically tested the effects of giant-planet close encounters on the orbital stability of their satellites," Matthew Clement, a research scientist at the Johns Hopkins University Applied Physics Laboratory and the study's first author, told Live Science in an email.

Replaying cosmic history

For their analysis, the researchers turned to computer models of the early outer solar system. Each model tracked the trajectories of the giant planets and a thousand planetesimals over 20 million years.

From a previously constructed database of 100,000 of these models, the team identified a smaller subset of 122 simulations with final configurations broadly similar to those of the present-day giant planets. Roughly two-fifths of this subset's simulations started with five giant planets, while the remaining began with six. Then, the team "'re-played' these encounter sequences with the giant planets satellites in place," Clement said.

The simulations showed that the extra giant planet (or planets) ping-ponged among their neighbors, before finally being kicked out of the system. But the simulations also revealed an unexpected result: Jupiter's moons remained stable mostly in the simulations with two extra ice giants, while Uranus' moons remained stable in those with just one extra giant planet. In other words, Jupiter's and Uranus' moons appear to have been preserved in separate events ‪—‬ an outcome the researchers found surprising.

The scientists noted that three of Jupiter's big moons — Io, Europa and Ganymede — exist today in an intricate resonance of 1:2:4. In other words, Io completes four orbits of Jupiter for every two of Europa and one of Ganymede. Such a delicately balanced dance suggests that Jupiter's moons have remained largely untouched since they formed and thus favors the existence of two extra ice giant planets, the researchers said.

Planet ping-pong

While ping-ponging between the gas giants and Uranus, these supplemental planets likely destabilized Uranus' moons, causing them to collide. Such collisions would have at least partially fragmented the moons and vaporized volatile materials like ice, which later accumulated on the remnants, possibly explaining why Uranus' moon Miranda has 50% more ice than the planet's other moons, the researchers suggested.

But this isn't the only possibility. Two simulations yielded a scenario resembling the present-day solar system, in which both Jupiter's and Uranus' satellites survived the same instability. In those cases, only one extra ice giant planet was involved. Therefore, further simulations will be needed to discern whether there was one extra ice giant or two, the researchers said in the study.

Little can be inferred about the now-missing planets, except for their masses. In the five-giant-planet scenarios, the one extra planet had a mass similar to that of Neptune, while in the six-planet cases, the two extra planets had masses between those of Earth and Neptune, making them "super-Earths."

"Given that the masses are not too different from Uranus and Neptune, [the long-lost planets'] physical properties probably resembled those planets," study co-author Nathan Kaib, a senior scientist at the Planetary Science Institute in Tucson, Arizona, told Live Science by email.

Although the researchers aren't planning to actively research the fugitive planets, they will continue studying Uranus' moons to identify signatures that show they were disrupted and to determine "the actual consequences of what happens if the satellites do go unstable," Clement said.

The team’s research was published online March 25 in the journal Icarus.

See how well you know our planetary neighborhood with our solar system quiz!

Throughout its history, Earth has been bombarded with countless meteorites. About 80,000 have been found so far, but one specific group is exceedingly rare — and scientists now think they could be evidence for a long-dead proto-world that used to orbit the sun.

That rare group is the "angrites," which account for just 0.09% of all meteorites. They’re among the oldest known rocks in the solar system, forming within just a few million years after the solar system began 4.56 billion years ago. They also contain exceptionally low levels of silica (silicon dioxide), which is a key ingredient of most asteroids and rocky planets.

One angrite meteorite, dubbed NWA 12774, (pictured here in cross-polarized light) was discovered in the Sahara Desert in 2019. And a new study into this space rock suggests that it could be the first definitive evidence of a long-lost protoplanet that once existed in the early solar system. (NWA stands for Northwest Africa, a designation given to every meteorite found in this region.)

The findings, published July 1 in the journal Earth and Planetary Science Letters, hint that this “planetary embryo” — if it existed — was made of angrite and may have been as big as the moon or even Mars. It’s thought to have orbited the sun before crashing into another celestial body and shattering into rubble billions of years ago; cue angrite meteorites falling to Earth.

In addition to its low silica content, NWA 12774 contains clinopyroxene, a mineral commonly found in Earth’s crust and mantle. This clinopyroxene is also unusually rich in aluminum, indicating that it formed under extremely high pressure — possibly a high-energy collision.

Such pressures could not have existed inside a small asteroid, hinting that the parent body of the angrites must have had a radius of at least 621 miles (1,000 kilometers), the researchers wrote. The sharp edges on NWA 12774 further suggest it formed near the surface, implying the parent body was even larger — with a radius of up to 1,118 miles (1,800 km). For comparison, Earth’s moon has a radius of 1,080 miles (1,737 km), and Mars has 2,106 miles (3,390 km).

“It’s incredible to think there was once [another] world this large,” study first author Aaron Bell, a petrologist at the University of Colorado Boulder, said in a statement. “We only know it existed because a few fragments of it happened to land on Earth. These meteorites preserved evidence of a completely different pathway through which early planets developed.”

Due to the lack of silica in the angrites, scientists had previously theorized that these meteorites originated from small asteroids. But the new findings challenge that view.

If they did originate from a protoplanet, then the world that could have formed from this "embryo" would have likely looked much different than the rocky planets we see today.

“The materials that formed the angrite parent body are fundamentally different from the ingredients of Earth and Mars,” said Bell. “It points to a distinct and separate evolutionary path in planetary formation in the early history of our solar system.”

It is unclear exactly what happened to the lost protoplanet. However, the researchers speculate that some of its fragments may have become the building blocks of other terrestrial planets, including Earth.

See more Space Photos of the Week

In a first-of-its-kind discovery, astronomers claim they have directly measured the magnetic fields of multiple planets beyond our solar system — potentially providing a crucial new tool in the search for habitable planets and alien life.

Magnetic fields exert a vital influence on planetary atmospheres and, therefore, their ultimate fate and prospects for habitability. We know, for example, that Earth's magnetic field has long protected our planet from harmful radiation, allowing our world to become a flourishing blue-green planet while inert Mars has grown barren and ostensibly dead.

The importance of a guardian magnetosphere is clearly evident. Yet magnetic fields on exoplanets, or alien worlds that orbit stars beyond our solar system, have remained poorly constrained, until now.

In a study published Tuesday (June 2) in the journal Nature Astronomy, a massive, multinational team of astronomers observed seven sizzling planets and found that their winds were slower than expected, suggesting that magnetic fields were slowing them down.

"This breakthrough opens a completely new window on exoplanet research," study co-author Julia Seidel, an astronomer at the Lagrange Laboratory in Nice, France, said in a statement. "It's the first time we can compare the magnetic environments of other worlds — a key step toward ultimately understanding which planets can stay alive, keep their water, and perhaps even, one day, host life as we know it."

Unexpected astronomy

The researchers were not specifically seeking exoplanetary magnetic fields. Instead, they sought to determine whether winds throughout the cosmos behave similarly on hot planets.

So they focused on seven "ultra-hot Jupiters," or sizzling gas giants swirling so close to their stellar parents that they're tidally locked, with one side always facing their star and the other side perpetually drenched in darkness.

Under such intense stellar irradiation, these seven planets attain estimated equilibrium temperatures of approximately 2,600 Kelvin (over 4,200 degrees Fahrenheit), whipping up unimaginable winds ranging from nearly 4,500 miles (7,200 kilometers) per hour to almost 16,000 mph (25,000 kmh). For comparison, our own not-so-hot Jupiter only manages to power winds to a relatively tame 900 mph (1,500 kmh).

The researchers clocked these otherworldly wind speeds using the ESPRESSO instrument on the European Southern Observatory's Very Large Telescope in Chile and the MAROON-X instrument on the Gemini North telescope in Hawaii.

These are both spectrographs, which are tools that split a celestial object's light into its constituent wavelengths to reveal its atmospheric composition. Accordingly, these observations allowed the astronomers to measure wind speeds by tracing the movement of iron through the atmospheres of these exoplanets.

A counterintuitive discovery

In doing so, they revealed several surprises. First, wind speeds on these hot, gassy planets actually declined with temperature — the hotter the planet, the lower the wind speed.

"This is totally counterintuitive because, all things being equal, hot planets have more energy to accelerate the winds," study co-author Vivien Parmentier, an astronomer and professor at Lagrange Laboratory, explained in a separate statement. "Something must happen that slows down the wind speeds for hotter objects."

The researchers concluded that the magnetic fields may be responsible for putting the "brakes" on these winds, by slowing the movement of charged particles in the atmospheres of these exoplanets.

Perhaps unexpectedly, the research suggests that these magnetic fields are only several gauss in strength — rather than hundreds of gauss, as predicted by some models. Such values are on par with the much colder gas giants in our solar system. This finding may therefore also help to reconcile predictive models for planetary magnetic fields.

Overall, this breakthrough study may set the standard for detecting magnetic fields around planets beyond our own. Applying this technique elsewhere could guide future searches for potentially habitable worlds, an ever-appealing prospect as next-generation facilities begin aiming their electric eyes toward other possible Earths throughout the universe.

A phenomenon that was thought to be impossible on Mars is squeezing the Red Planet's atmosphere like toothpaste from a tube, a new study finds. The surprising discovery, uncovered by a NASA spacecraft during a powerful solar storm, could change how we think of dangerous space weather throughout the solar system, researchers say.

The unlikely phenomenon, dubbed the Zwan-Wolf effect, was first discovered on Earth in 1976 and occurs when "charged particles are squeezed like toothpaste coming out of a tube along magnetic structures called flux tubes," NASA representatives wrote in a statement. These flux tubes are located within Earth's magnetosphere, the invisible field that is generated by the movements of our planet's molten metal core and shields us from radiation.

While similar phenomena likely occur on Jupiter and Saturn, experts have long assumed that the Zwan-Wolf effect could not happen on Mars because our next-door neighbor's core has long since solidified and, therefore, does not generate a proper magnetosphere. (This is also why the Red Planet has such a thin and wispy atmosphere; without magnetic shielding, most of its gases have been stripped away by solar storms.)

But in the new study, published May 18 in the journal Nature Communications, researchers analyzed data from NASA's Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft, which has been orbiting the Red Planet since 2014 (though NASA lost contact with it last year), and found something strange.

In December 2023, a powerful coronal mass ejection (CME) erupted from the sun and slammed into Mars, temporarily scrambling the remnants of its upper atmosphere and revealing disturbances that could be explained only by the Zwan-Wolf effect.

"When investigating the data, I all of a sudden noticed some very interesting wiggles," study lead author Christopher Fowler, a planetary scientist at West Virginia University, said in the statement. "I would never have guessed it would be this effect," he added.

Unlike on Earth, where the Zwan-Wolf effect occurs tens of thousands of miles above our planet's surface, the Martian equivalent occurs in the ionosphere — the upper part of the atmosphere, which is full of ionized gas, or plasma — at an altitude of around 125 miles (200 kilometers).

"No one expected that this effect could even occur in the atmosphere," Fowler said. "That's what makes this even more exciting."

Mars' Zwan-Wolf effect is likely powered by a localized magnetic field at the boundary where solar wind — the constant stream of charged particles that shoots from the sun — collides with ionospheric plasma, the researchers wrote. This means it is probably happening all the time, but we only realized it now because the radiation from the CME exaggerated the effect.

As a result, experts are keen to study this phenomenon further to better understand how it may impact future missions to Mars, since changes to the ionosphere will likely affect orbiting spacecraft, communications equipment, and the levels of harmful radiation that reach the planet's surface.

"Knowing how space weather interacts with Mars is essential," study co-author Shannon Curry, a research scientist at the Laboratory for Atmospheric Space Physics at the University of Colorado Boulder and the principal investigator for MAVEN, said in the statement. It is, therefore, vitally important to understand "these links between our host star and the Red Planet," she added.

Now that we know the Zwan-Wolf effect can occur within planetary atmospheres, we may also soon discover it on other solar system worlds, such as Venus and Saturn's largest moon, Titan, the researchers hypothesized.

Bizarre Venus surface formations (or coronae) are likely key to understanding our twin planet's heretofore inscrutable interior. Using NASA Magellan spacecraft data from decades past, Anna Gulcher, an earth and planetary scientist at Germany's University of Freiburg, have created innovative new 3D models of the largest coronae to better understand Venus' puzzling geodynamics.

The team used data from the Magellan spacecraft's radar sensors, which officially ceased functioning in 1994, to get a closer look at the coronae's surrounding topography and gravitational signatures.

Coronae display extraordinary diversity in size, morphology, topography, gravity signatures, and tectonic setting, indicating that they do not represent a single formation mechanism, but instead reflect a spectrum of dynamic processes, Gulcher and colleagues write in a paper presented at the European Geosciences Union's 2026 General Assembly in Vienna.

The updated database includes 741 coronae which span Venus' surface.

They are huge circles of fracture systems that we think are basically the surface expression of a plume of hot material moving upwards from the interior of the planet, Gulcher told me at EGU26 in Vienna.

Understanding these structures is critical not only for deciphering Venus' geodynamic regime, but also for assessing whether similar processes may have operated on the early Earth, Gulcher and colleagues write in the EGU paper.

By combining gravity and topographic data with geodynamic simulations, the study identifies possible warm mantle upwellings beneath 52 coronae and presents perhaps the strongest evidence that different plume-related tectonic processes occur there, says Gulcher. The work also shows that current gravity data can miss many active tectonic signals, meaning activity on Venus could be more widespread than currently detectable, she says.

As For Why They Are Circular?

We think they are formed by something circular in shape from the interior, says Gulcher. A magma plume, for instance, that is hotter than the surrounding material can cause a lot of uplift of the crust, which creates these rings, she says.

The coronae are thought to have been the result of a lot of mantle convection.

Mantle convection is the movement of the mantle (or rocky layer between the core and crust) of any planet, where it can spread outwards and drive plates to move laterally, says Gulcher. It's the cycle of upward and downward movement of the mantle over a very long time scales, she says.

Planetary scientists still debate whether Venus ever had any geophysical process resembling atmospheric carbon recycling. The most significant would have been full-scale plate tectonics, the theory that ascribes our planet's lithosphere as being divided into giant moving plates. The idea is that such plates frequently collide causing earthquakes, volcanic eruptions as well as the continuous recycling of carbon in and out of our atmosphere.

Earth is beyond fortunate for having the unique ability to evolve plate tectonics, which enabled our atmosphere to remain stable over billions of years. Plate tectonics is arguably what differentiates the ability of any given rocky planet to evolve intelligent life.

On Earth, carbon is recycled back into the mantle very efficiently, says Gulcher.

That's in part because large scale water oceans at Earth’s surface created hydrous (or water rich) rocks. Such rocks are prone to become weaker and more pliable much faster than lithospheric rocks on a dry planet like Venus. In fact, Venus may never have had a large water ocean; that's an important conundrum that upcoming missions to Venus' surface hope to solve.

It's now thought that such water oceans are what's needed to create plate boundaries. That's when a planet's lithospheric rocks become much more pliable and thus more prone to break up and separate into separate into movable tectonic plates.

In contrast, without oceans, Venus likely only had very limited carbon recycling via tectonic and resurfacing processes, says Gulcher.

More details should come with future in situ data taken at Venus.

Future missions, such as VERITAS and EnVision, will significantly enhance our ability to analyze coronae with unprecedented detail in surface and subsurface structure, and increased topographic and gravity resolution, Gulcher and colleagues noted in a 2025 paper in the journal JGR Planets.

As For Earth?

Plate tectonics have been stable here on Earth for at least 3 billion years, says Gulcher. This global destruction of material and formation of material allowed our planet to lose a lot of heat and also to recycle material back into the mantle, she says. This continuous cycle allowed our planet to have stable surface conditions over billions of years, says Gulcher.

What haunts Gulcher most about Venus?

We see structures on Venus that are so earthlike yet also show a few very important differences, says Gulcher. With the available data, we don't fully understand how it can look so similar but be so different, she says.

The original version of this article was published on Universe Today.

Jupiter's giant moon Ganymede is the only known moon to have its own magnetic field — and it may be heating up in a process "not yet observed anywhere else," new research suggests.

One of the four Galilean satellites swirling around Jupiter, Ganymede is the largest moon in the solar system. At nearly 3,300 miles (5,300 kilometers) in diameter, it's more than 1,000 miles (1,600 km) wider than Earth's moon and slightly bigger than Mercury, our tiniest planetary tot. (Jupiter has more than 100 confirmed moons, with the largest four known as the Galilean moons.)

This standout satellite's intrinsic magnetic field — discovered by NASA's Galileo spacecraft in 1996 — is generated through a process called a dynamo, powered by the electrically conductive, churning liquid iron in its core.

Yet the mechanism through which this process emerged is hotly debated.

"Many formation studies suggest that Ganymede formed too cold to start with a metal core," study co-author Kevin Trinh, a planetary scientist at Caltech, said in a statement. "Meanwhile, many modeling studies of Ganymede's dynamo assume that Ganymede formed its metal core roughly when the moon itself formed, as Earth did. Both of these things cannot be simultaneously true."

So, in a paper published May 6 in the journal Science Advances, researchers propose a new topsy-turvy mechanism that may have formed Ganymede's mysterious metallic core and dynamo later rather than earlier, as molten iron blobs sank into the massive moon's core. This activity may be ongoing today.

Hot or cold start?

The "warming-driven dynamo" presented in the study is the opposite of traditional dynamo-origin ideas, which propose that they form early in large bodies like Earth and then gradually cool.

For example, metallic core formation in planetary bodies is thought to have occurred within around 200 million years of the solar system's formation. Yet moons may be too small to hold enough heat from their birth to power this process.

But all hope is not lost, because a body formed from a "cold start" may still be able to grow a magnetic-field-generating core, the researchers' new model suggests.

This model integrates and simplifies Ganymede's characteristics, such as its composition and core temperature, assuming its core is composed of iron and iron sulfide, because these components have lower melting temperatures.

In this model, molten metal blobs sink into Ganymede's innards to feed its core and whip up its magnetic field. They are warmed through two main mechanisms: radioactive heating and tidal heating.

First, as heavier radioactive isotopes decay into lighter elements, they release heat. Second, Jupiter's gigantic gravitational influence squeezes and stretches Ganymede as the moon whirls nearer and farther from its parent, as if "kneading" a planet-size piece of rocky, icy dough. The resulting inner friction generates heat. This heat powers the dynamo that gives Ganymede its magnetic field.

Altogether, this hypothesis does not preclude the possibility that Ganymede formed with a magnetic-field-producing core.

Alien implications?

But if "cold start" cores exist throughout the universe, it could present a previously unexplored process for magnetic fields to form and protect aging worlds, perhaps facilitating an intriguing implication in the search for extraterrestrial life.

Magnetic fields are necessary to protect life from harmful solar and cosmic radiation, making them a prerequisite in most searches for habitable planets. But a little magnetism can go a long way: As is apparent on Earth, with a magnetic field significantly weaker than a fridge magnet, even a modest magnetosphere can transform the outlook of planetary bodies.

"There could be young rocky exoplanets or exoplanets with lower radioactive isotope abundances (i.e., slower heating) that would be favorable for a recent warming-driven dynamo," Trinh told Live Science in an email. "The challenge is that no one has detected an exoplanet dynamo so far."

Is it just us, or is the Red Planet looking a lot bluer than usual?

NASA's Psyche spacecraft returned this colorful snapshot of Mars after completing a close flyby of the planet last week, marking a major milestone in the probe's long journey to the metal-rich asteroid 16 Psyche. The spacecraft passed within 2,864 miles (4,609 kilometers) of the Martian surface on May 15, taking a suite of color images, including this close-up of the double-ringed Huygens crater and the heavily cratered southern highlands surrounding it.

Aside from the image of Huygens crater, Psyche obtained close-ups of wind blowing over craters in the Syrtis Major region and a high-resolution view of the water-ice-rich south polar cap of Mars.

In other spectacular images taken as Psyche approached and departed the planet, Mars appears as a thin crescent — a rare perspective afforded by Psyche's high angle of approach. Researchers also observed sunlight scattering through Mars' dusty atmosphere, creating a brighter-than-expected glow around the edge of the planet. As it left the vicinity of the Red Planet, Psyche got an image of an almost fully lit Mars, which included its south polar cap and the Valles Marineris canyon.

"We've captured thousands of images of the approach to Mars and of the planet's surface and atmosphere," Jim Bell, the Psyche imager instrument lead and a planetary scientist at Arizona State University, said in a NASA statement. It was part of an effort to calibrate Psyche's multispectral cameras well in advance of its arrival at asteroid 16 Psyche. "As the spacecraft continues its journey after the flyby, we'll continue calibration imaging of Mars for the rest of the month as it recedes into the distance," Bell added.

NASA's solar-powered Psyche mission launched Oct. 13, 2023, on a complex route to the asteroid belt. The quickest way to get somewhere in the solar system isn't to use propellant to fly directly but to slingshot around a moon or planet, effectively using gravity and orbital motion to accelerate a spacecraft. 16 Psyche is in the main asteroid belt between Mars and Jupiter, where it orbits the sun about three times farther away than Earth does.

According to NASA's Jet Propulsion Laboratory, the recent Martian flyby increased Psyche's speed by approximately 1,000 mph (1,600 km/h) and shifted its orbital plane by about 1 degree relative to the sun.

Following the maneuver, NASA engineers used the agency's Deep Space Network to confirm that the spacecraft remains on the correct trajectory for its scheduled arrival at asteroid Psyche in August 2029, where it will go into orbit and conduct detailed mapping and scientific observations. The asteroid is thought to be the exposed core of a planetesimal, a building block of an early planet.

The abundant metals on the asteroid are thought to be worth many quadrillions of dollars — though, at the moment, there is no feasible plan for extracting them.

What do you know about the Red Planet? Test your knowledge with our Mars quiz!

One of Neptune's largest moons has stuck around the neighborhood much longer than scientists previously thought — in fact, it may be the sole survivor of the planet's earliest days.

Nereid, Neptune's third-largest moon, is probably the only moon left over from when the ice giant formed early in the solar system's 4.5 billion-year history, a new analysis of James Webb Space Telescope (JWST) data suggests.

The results, published Wednesday (May 20) in the journal Science Advances, contradict the previous story about Nereid's history told in the decades since its 1949 discovery: that Neptune "captured" the 220-mile-wide (350 kilometers ) moon from an icy well of bodies in the outer solar system known as the Kuiper Belt.

JWST's observations were key to this realization, said first study author Matthew Belyakov, a graduate student in planetary science at Caltech. "What JWST did for Nereid is it confirmed that it had a lot of water ice, and gave us the overall shape of the spectrum [of light]," Belyakov told Live Science in a phone call.

The telescope's observations of the moon revealed a composition that's significantly different from that of known Kuiper Belt objects, he continued. Crucially, JWST has been in space long enough to allow direct comparisons against Kuiper Belt worlds that the telescope itself has observed. "We're able to compare apples to apples," Belyakov added.

The moon-stealing planet

Previously, astronomers assumed that Nereid was "captured" by Neptune's gravity, like the planet's other known moons are suspected to have been. This is due to Nereid's orbit, which is highly elliptical — suggesting the moon was snatched from a previous, more stable orbit in the Kuiper Belt.

But that hypothesis is challenging to prove, given that Neptune has 16 known moons. Most of those moons are small, aside from Triton, which is slightly smaller than Earth's moon. The system is made up largely of small moons in irregular orbits.

"The trouble at Neptune is that we don't have any regular satellites really, whatsoever," Belyakov said.

Triton, Neptune's largest moon, represents 99% of the Neptunian moon system's mass and is on a "retrograde," or backward, orbit, Belyakov added. Triton is clearly a captured object ‪—‬ not only because of its odd orbit but also because observations have shown that its composition is more similar to Pluto's than to Neptune's, he said.

In the new study, the authors ran simulations of Triton's capture from the Kuiper Belt and how it may have affected the existing moons of Neptune. The simulations show that Triton's arrival gave the original Neptune moons a tremendous kick. "Triton gets captured and alters the original system, and creates a Nereid-like object," Belyakov explained.

Moon mysteries

To shore up this theory, Belyakov hopes to get a better look at Nereid in higher resolution. JWST is in high demand by astronomers, and Belyakov's team, which includes noted moon dynamicist and Caltech professor Konstantin Batygin, got a few minutes of telescope time using the lowest-resolution mode of JWST's Near-Infrared Spectrograph (NIRSpec). The team plans to submit an application for use of a higher-resolution mode of NIRSpec in a future call for telescope observations, he said.

These observations have implications not only for Neptune but also studies of exoplanets and gas giants, Belyakov emphasized.

"The big picture is that really we don't quite understand how moons around Uranus and Neptune form," Belyakov said. "What we're finding generally, in the study of exoplanets, is that planets of the size of Uranus and Neptune are pretty much the most common type of planet. And so if we don't understand how moons around these objects form, that's a really big problem."

The histories of Uranus and Neptune are making the study more challenging, he noted. Uranus is weirdly tilted on its side, perhaps due to a big collision with another object eons ago, which means its first generation of moons likely no longer exists.

"And at Neptune, we're also missing that first generation of moons," Belyakov said.The planet's innermost moons today were reforged from the original generation of moons that broke apart in the wake of Triton's arrival, the authors noted.

"So perhaps," he continued, "Nereid is the only original, sort of intact, remnant of satellites that originally formed around these planets. That would be a very exciting result, because it means that we have this one window to explore and understand satellites."

The scientists operating NASA's Curiosity rover are breathing a sigh of relief after successfully removing a troublesome rock that got stuck on the end of the Mars rover's robotic arm for nearly a week. Video footage shows the robot "struggling" to shake off its pesky passenger by tilting, rotating and vibrating its metallic limb.

The first-of-its-kind fiasco began when Curiosity came across a fairly innocuous-looking rock, dubbed Atacama (after the Chilean desert on Earth), while exploring the slopes of Mount Sharp, which stands at the heart of Gale crater, near the Red Planet's equator. The rock was around 1.5 feet (46 centimeters) in diameter, 6 inches (15 cm) thick and approximately 28.6 pounds (13 kilograms), making it an ideal candidate for further analysis.

On April 25, Curiosity attempted to drill into Atacama to extract a sample that might be analyzed within its onboard "wet chemistry" laboratory. Although the robot's drill arm successfully bored into the rock, it quickly became clear that something had gone wrong.

"When the rover retracted its arm, the entire rock lifted out of the ground, suspended by the fixed sleeve that surrounds the rotating drill bit," NASA representatives wrote in a statement. "Drilling has fractured or separated the upper layers of rocks in the past, but a rock has never remained attached to the drill sleeve."

This posed an entirely new problem to the scientists controlling Curiosity, who "went to work to develop a plan to extract the drill bit from the rock," Bill Farrand, a senior research scientist at the Space Science Institute in Boulder, Colorado, who worked on NASA's Mars Exploration Rover mission, wrote in a NASA blog post. But this ended up being something of a "struggle," he wrote.

The Curiosity team initially tried to remove Atacama by "vibrating the drill to shake off the rock," but they were unsuccessful. On April 29, they tried to vibrate the drill while reorienting the arm. However, this only managed to shake tiny, sand-like fragments off the rock.

Finally, on May 1, the rock dislodged after the team attempted "tilting the drill more," as well as rotating, vibrating and spinning the drill bit. They had planned to do this multiple times. However, the rock separated at the first attempt and fell back to the Martian surface, Farrand wrote.

Images show that Atacama fractured into at least two pieces upon impacting the ground.

Unfortunately, the sample, or drill tailings, were "lost from Atacama as part of the effort to dislodge the drill bit from the rock," Farrand wrote. The Curiosity team is, therefore, "seeking a more firmly rooted drill target in order to collect drill tailings for analysis," he added.

A busy few months

Curiosity has been through a lot since it first landed on Mars in 2012, but the past few months have been particularly eventful for the wandering robot.

In late April, researchers revealed that the rover had collected seven organic molecules at once — the largest single haul on Mars to date — to go along with a "giant string" of hydrocarbons discovered in February. (Both of these findings offer clues about the potential for ancient alien life on the Red Planet.)

A few weeks earlier, in early April, Curiosity also snapped photos of dozens of what look like "dragon scales" scattered across the ground. And in March, the robot found ruby-like crystals hidden within rocks similar to Atacama.

Prior to these findings, the rover had spent more than six months closely studying a series of ridge-like features, dubbed boxwork, which look like giant rocky spiderwebs zigzagging across the Red Planet's surface, and, most recently, discovered that they are covered in tiny, egg-like structures.

Mars quiz: Is your knowledge of the Red Planet out of this world?

Astronauts could complete a round trip to Mars in less than a year someday, potentially cutting current mission timelines in half, according to a new study that drew inspiration from asteroid trajectories.

Under current mission profiles, reaching Mars, which is located about 50% farther from the sun than Earth is, takes roughly seven to 10 months. Because Earth and Mars align for fuel-efficient transfers only every 26 months, astronauts must wait for a return window, stretching a full round trip to nearly three years.

However, the new findings, published online in the journal Acta Astronautica in April, suggest that early, imprecise orbital estimates of near-Earth asteroids — which were historically used to assess impact risks, before being discarded in favor of more precise data — may contain valuable geometric clues for designing faster interplanetary routes.

"Maybe this can change the idea that we need more than two years to go to Mars and return," study author Marcelo de Oliveira Souza, a cosmologist at the State University of Northern Rio de Janeiro in Brazil, told Live Science.

"I was not looking for this"

Souza first stumbled on the idea in 2015, when he was studying near-Earth asteroids. One object in particular, 2001 CA21, caught his attention because early estimates suggested it followed a rare path crossing both Earth's and Mars' orbital zones.

Although later measurements refined the asteroid's true trajectory, its initial geometry during the October 2020 opposition — when Earth and Mars were aligned on the same side of the sun, and closest together in their orbits — hinted at the possibility of "ultra-short" routes between the two planets, Souza noted in the paper.

"This was a surprise for me — I was not looking for this," he told Live Science.

As more observations allow astronomers to refine an asteroid's orbit, those early trajectories change, so someone analyzing it later wouldn't have seen the same path, Souza added. "Maybe I was in the right place at the right time," he said.

Round trip to Mars?

For the October 2020 opposition, Souza's calculations showed that a very fast, roughly 34-day trip from Earth to Mars is geometrically possible if a spacecraft follows a path similar to the asteroid's early orbital plane.

However, such a trajectory would require departure speeds of around 32.5 kilometers per second, well beyond current rocket capabilities, and a spacecraft would arrive at Mars traveling around 64,800 mph (108,000 km/h) — too fast for existing landing systems to handle safely, Souza noted in the paper.

Instead, Souza used the asteroid-inspired geometry to explore possible trips during future Mars oppositions in 2027, 2029 and 2031. By using a standard method for calculating paths between two points in space (called the Lambert analysis) and constraining those paths to remain within about 5 degrees of the asteroid's orbital tilt, Souza found that only the 2031 alignment offered a viable opportunity for rapid travel using near-term technology.

In that window, a round-trip mission from Earth to Mars could be completed in just 153 days, or roughly five months, according to the study.

In that scenario, a spacecraft would depart Earth on April 20, 2031, at about 27 kilometers per second, arrive at Mars by May 23 after a 33-day journey, spend about 30 days on the surface, depart June 22 and return to Earth by Sept. 20, with the return leg taking roughly 90 days.

Souza also identified a lower-energy alternative within the same window, requiring a launch at about 16.5 kilometers per second for a mission lasting about 226 days, or about 7.5 months ‪—‬ still significantly shorter than current mission timelines.

Still, the concept remains largely theoretical and would depend heavily on mission specifics — including spacecraft design, payload mass and propulsion capabilities — all of which would shape whether such fast transfers are feasible in practice.

The method, however, could still prove useful as a way to narrow the search for viable trajectories. The required velocities are comparable to those achieved by missions such as New Horizons — the NASA probe, which, when launched in 2006 on a mission to flyby Pluto at 16.26 kilometers per second, was the fastest human-made object ever launched from Earth.

Such high-speed trajectories could be within the reach of next-generation rockets such as SpaceX's Starship or Blue Origin's New Glenn, Souza told Live Science.

What do you know about the Red Planet? Test your knowledge with our Mars quiz!

Scientists may have detected more than 10,000 never-before-seen exoplanets in a single survey, potentially tripling the number of known alien worlds in one fell swoop. The record-breaking haul was possible thanks to a new algorithm that helped researchers analyze more than 80 million stars — revealing subtle clues that would otherwise be "impossible" for us to see.

Since the first alien planet was spotted in 1995, the number of exoplanet discoveries has slowly risen in line with new technologies, such as the James Webb Space Telescope, which are better equipped to spot these weird alien worlds. In September 2025, astronomers revealed that the number of confirmed exoplanets had surpassed 6,000, and nearly 300 have been added to the list since then, according to NASA.

But in a new study uploaded April 20 to the preprint server arXiv, researchers report that they've uncovered an astonishing 11,554 exoplanet candidates at once. If all of them can be confirmed, it would bring the total number of exoplanets to nearly 18,000, which is almost triple the current total. (The study has not been peer-reviewed yet.)

Using a machine learning algorithm, the team analyzed the light curves of precisely 83,717,159 stars captured by NASA's Transiting Exoplanet Survey Satellite (TESS), a car-sized space telescope that has been circling Earth since 2018. By looking for subtle dips in the stars' brightness, astronomers can tell when a planet has likely passed in front of, or transited, its home star.

This revealed more than 11,000 exoplanet candidates, of which 10,052 had never been seen before. (Other scientists had previously identified the rest, but they are not yet confirmed as exoplanets.) Around 87% of the candidates were spotted transiting twice or more, allowing the researchers to calculate the planets' orbital periods, which range from 0.5 to 27 days, according to StellarCatalog.com.

But the researchers didn't stop there. To test the validity of their model, they attempted to confirm one of the new candidates themselves.

Using one of the 21-foot (6.5 meters) Magellan telescopes in Chile's Atacama Desert, the team identified a "hot Jupiter" exoplanet, dubbed TIC 183374187 b, that orbits a star around 3,950 light-years from Earth — right where the algorithm predicted.

The confirmation of TIC 183374187 b hints that at least a few of the other exoplanet candidates will also end up being confirmed. However, first these planets must be verified by independent surveys and studied in greater detail, which can take months or years to do properly.

Finding "impossible" planets

TESS was specifically designed to detect transiting objects, and it has already discovered 882 confirmed exoplanets — roughly 14% of the current total — so it may seem strange that no one has seen most of the new candidates until now. However, there is a good reason why.

Most researchers prioritize analyzing the light curves of the brightest stars in the TESS dataset, because transit events for these stars are much more noticeable and easier to confirm. But there are many more faint stars that end up being captured in the telescope's wide-field photos.

In the new study, the researchers looked at every star — up to 16 magnitudes dimmer than the normal threshold for a transit study — from TESS' first wide-field image. The researchers call this idea the T16 project.

The extreme dimness of these light curves makes it extraordinarily hard to spot potential transit events, which is why they are normally overlooked. To overcome this hurdle, the team created a machine learning algorithm that learned to distinguish subtle clues that a transit had potentially occurred. (Machine learning is a subset of artificial intelligence where computers learn from data to make predictions, rather than being explicitly programmed.)

A computer program also allowed the team to analyze the enormous dataset, which would "be impossible" for humans to sort through on their own, Universe Today reported.

"This work shows that large-scale, machine-learning-assisted transit searches can significantly expand the census of transiting planet candidates, particularly around faint stars," researchers wrote in the paper.

Unfortunately, the brief orbital periods of the exoplanet candidates hint that they are probably too close to their home stars to support life as we know it. (This is because more distant planets orbit their stars less often and are less likely to align with an observer for a transit.)

A section of Mars is covered in a surprising number of features that look like clumps of giant, fossilized reptile scales, new photos reveal. But don't be alarmed ‪—‬ the strange structures did not originate from monstrous aliens. Instead, they may have ties to ancient water.

NASA's Curiosity rover snapped the photos of the peculiar rocks as it was driving toward Antofagasta — a relatively young, 33-foot-wide (10 meters) impact crater located on the slopes of Mount Sharp (also called Aeolis Mons), which stands in the larger Gale crater, near Mars' equator.

A pair of black-and-white photos of the "scales" was released by NASA April 14, while a close-up color image of the rocks was shared online the next day by Kevin M. Gill, a software and spaceflight engineer at NASA's Jet Propulsion Laboratory (JPL) who specializes in image processing. (The pics were captured April 7 and April 13, respectively — also called Sol 4859 and Sol 4865 in Martian time.)

The unusual shape and tight clustering of these rocks have drawn comparisons to the scales of reptiles such as crocodilians, while some commenters joked that the formations look dragon-like.

It is currently unclear how many of the scale-like rocks were photographed or how large they are, but they stretched across the ground "for meters and meters," according to an April 10 NASA blog post.

Although the researchers were not shocked to see these multifaced rocks, or "polygons," they were surprised by the sheer quantity of them in the area.

"Many of the rocks we've driven over have these incredible textures — thousands of honeycomb-shaped polygons crisscross their surface," Abigail Fraeman, a planetary scientist at JPL, wrote in the blog post. "We've seen polygon-patterned rocks like these before, but they didn't seem quite this dramatically abundant."

Polygons with a similar honeycomb-like shape have been seen before on Mars on both smaller and larger scales. In these past instances, the shapes were often tied to the drying of wet mud or ice crystals moving beneath the Martian surface. However, it is too early for scientists to tell exactly how the latest shapes formed.

Curiosity has collected "lots of images and chemical data that will help us distinguish between different hypotheses for how the honeycomb textures formed," Fraeman said.

Animal impostors

Before reaching Antofagasta, Curiosity spent the better part of a year studying a series of rocky ridges on Mount Sharp dubbed "boxwork." These features are also known as Martian "spiderwebs" because of how they zigzag across the ground, and the wandering robot recently spotted tiny, egg-like spheroids stuck to their sides. (The "webs" should not be confused with the infamous "Spiders on Mars," which are dark, arachnid-like features that litter the planet's surface.)

Since landing on the Red Planet in 2012, the rover has also snapped a series of other objects that look suspiciously animal-like, including a surprisingly realistic coral-like rock formation.

NASA's other Mars rover, Perseverance, has also seen its fair share of faux creatures since touching down in 2021, including a statuesque "turtle" poking its head out of a shell. And the fleet of spacecraft orbiting Mars has spied other unusual entities, including a "butterfly" crater and a Martian "dog" buried beneath the planet's north pole.

Most of these animal associations are the result of a phenomenon known as pareidolia, which is when the human brain sees or hears something significant in a random image or pattern.

Mars quiz: Is your knowledge of the Red Planet out of this world?

A massive dark patch lurking within a giant Martian crater has been creeping across the Red Planet's surface since the feature was first spotted 50 years ago, new photos reveal — and scientists are unsure exactly why this is happening.

The shadowy structure is a patch of ground covered with ash and volcanic rocks, such as olivine and pyroxene, from ancient eruptions that occurred millions of years ago, before Mars was considered geologically dead. It is located in Utopia Planitia, a roughly 2,000-mile-wide (3,300 kilometers) plain in Mars' northern hemisphere.

NASA's Viking probes first photographed the blackened ground in 1976, shortly after arriving at the Red Planet. Since then, several photos have shown that this feature is expanding across the surrounding landscape; these include new images from the European Space Agency's (ESA) Mars Express orbiter, which were captured in 2024 and released April 15.

It is unclear how large the shadowy feature is. However, sections of the patch's southern boundary have moved farther south by at least 200 miles (320 km), based on the latest photos from ESA. This suggests the dark terrain has been expanding by around 4 miles (6.5 km) per year.

Scientists are confident that the movement of the dark patch has something to do with Martian winds, which are known to scour the surface and kick up ash and dust.

"The spread of the ash over the last 50 years has two possible explanations: either it has been picked up and moved about by Martian winds, or the ochre dust that previously covered the dark ash has been blown away," ESA representatives wrote in a statement.

However, there is currently no clue as to which hypothesis is correct, they added.

Utopia Planitia

This region of Mars has been of great interest to scientists over the past half century. In 1976, the Viking 2 lander touched down in Utopia Planitia and carried out a series of "biological experiments" until its demise in 1980.

More recently, China's Zhurong rover also touched down there in 2021 and explored the giant plain before going dark in 2023. Chinese scientists have since used the Zhurong data to show that Utopia Planitia was most likely once covered with one of Mars' largest oceans, and they have even mapped out what they think was once a shoreline. The rover also may have detected clues of a surprising "climatic shift" in the region around 400,000 years ago.

Utopia Planitia is home to several large cracks in the ground, known as grabens, which are one of Mars' most unusual features and could also help provide clues to any tectonic activity that once rocked the Red Planet, according to ESA.

In addition, researchers think there is a significant amount of buried ice beneath the region, which could have big implications for the hunt for extraterrestrial life.

Mars quiz: Is your knowledge of the Red Planet out of this world?

Saturn may be famous for its rings, but it has long fascinated scientists for another reason: its restless atmosphere, which is shaped by fierce winds, stubborn megastorms and strange weather patterns that can linger for years.

Now, two new views from the James Webb and Hubble space telescopes are cutting through the ringed planet's clouds, giving researchers what NASA calls the "most comprehensive view of Saturn to date." Together, the images let researchers "slice" through Saturn's atmosphere at different heights.

The paired observations capture one of Saturn's strangest landmarks: the famous hexagon at the north pole. According to NASA, the faint edges of the six-sided jet stream appear in both images. These pictures could be some of the last high-resolution views of the hexagon until the 2040s, as Saturn's north pole is about to tip into 15 years of winter darkness.

Studying Saturn's atmosphere not only allows scientists to understand how large, planet-size storms grow and thrive but also gives further insight into how the planet formed and evolved over billions of years.

A planet seen two ways

In August 2024, Hubble took its visible-light image of Saturn as part of the Outer Planet Atmospheres Legacy program, a decade-long project that tracks the outer planets annually. The James Webb Space Telescope (JWST) captured its infrared image a few months later, in November 2024. Those observations, taken 14 weeks apart, showed the ringed planet shifting from northern summer toward its 2025 equinox.

The two telescopes saw very different Saturns.

While Hubble captured Saturn's pale-yellow bands and brilliant-white rings, JWST's infrared image revealed even more striking details. In the infrared view, Saturn's rings transformed into glowing blue "because they are made of highly reflective water ice," NASA representatives said in a statement. Saturn's poles also shone a strange gray-green, emitting light at wavelengths of about 4.3 microns. These emissions could be from either light scattering off of high-altitude aerosols or auroras, NASA suggested. (The telescope recently caught giant auroras shining on Uranus.)

As Saturn tilts into its southern springtime, both space telescopes will continue to keep their eyes on its atmosphere, perhaps revealing more about the planet's weather dynamics. Until then, Saturn is keeping some of its most interesting secrets hidden in the clouds.

Solar system quiz: How well do you know our cosmic neighborhood?

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Mars is hiding a clutch of ruby-like crystals in its rocks, observations from the Perseverance rover suggest, and astronomers say other precious minerals, like sapphires, could exist across the Red Planet, too.

An international team of researchers presented the findings, based on observations from spring 2025, March 16 at the 57th Lunar and Planetary Science Conference in Texas. These findings are currently under peer review and will appear in the journal Geophysical Research Letters.

The story begins a short time ago on a planet not too far away, when a roving robot the size of a compact car climbed the side of a 4 billion-year-old impact crater and began exploring its rim. On that ancient and stony rim, NASA's Perseverance rover found a curious scattering of pale-colored "float rocks" — out-of-place rocks that must have been transported there by impacts, geological activity or hydrological processes.

As scientists often do when faced with a curious specimen, they blasted it with a laser — specifically, the green laser from the Perseverance rover's SuperCam, situated atop its mast. This laser excites minerals, causing them to emit light at specific wavelengths. And because every element and compound emits certain wavelengths of light, this reveals a sample's chemical composition.

The corundum conundrum

The analysis showed that three of the laser-blasted float rocks exhibited clear signatures of the mineral corundum, with inclusions of the element chromium — crystals that match the chemical description of rubies. However, because the crystals are too small to be seen by Perseverance's imager, and their exact chemical composition is uncertain, the researchers aren't sure whether they have truly found Martian rubies or perhaps some other type of corundum.

"The different types of corundum are based on the chemistry," study co-author Valerie Payré, a planetary geologist at the University of Iowa, told Live Science via email. "Although corundum is Al2O3, there are minor elements like chromium, titanium, and iron that can be present."

"These elements will provide the color to the mineral, and the name of it," Payré added. "We cannot quantify the amount of chromium, and other elements like iron and titanium might be present too. It is thus difficult to conclude whether they are rubies or other types of corundum [like sapphires]."

The team ultimately classified the crystals as corundum and declined to guess about the variety without more chemical evidence.

Corundum is a mineral made of aluminum and oxygen. It is one of the hardest known natural substances, approaching the toughness of diamonds. Pure corundum is colorless, but microscopic impurities imbue it with brilliant hues. Iron or titanium inclusions yield brilliant blue sapphires, while chromium produces even rarer, resplendent rubies.

However, anyone holding out hope for a future Martian-gemstone-studded necklace may be disappointed. The corundum crystals found within the float rocks are tiny —‬ less than 0.2 millimeters (0.008 inches) in diameter.

Could slightly larger Martian rubies exist? "Yes, possibly," study co-author Olivier Beyssac, a senior scientist at the French National Center for Scientific Research, told Live Science via email. "Anyway corundum is pretty rare on Earth and rarely present as big crystals so one could expect the same on Mars."

Cosmic impacts?

It's also likely that the crystals formed under different conditions than those on our planet. On Earth, corundum is created through metamorphic and igneous processes, in which intense heat and pressure, facilitated by tectonic activity, transform existing rocks into potential gemstones.

But because there is no conclusive evidence for plate tectonics on Mars, the researchers suggest that the ruby-like crystals on the Red Planet may have formed through cosmic impacts.

"The impacts provide high temperatures and high pressures, which can produce corundum. Hydrothermal fluids are also generated," Payré explained. Yet the researchers must find additional samples, at their origin, to describe their formation mechanism.

"As of now, the corundum crystals were found in small pebbles that are coming from elsewhere, i.e., they are out of context. It is therefore difficult to constrain the full story," Payré said.

Rubies are far from the only spectacular stones found at Jezero crater, and further research may reveal sapphire-like stones there as well. In the past, scientists also discovered signs of other potential gemstones elsewhere on Mars, including quartz and opal — suggesting that our red planetary neighbor is a gem laboratory.

Mars quiz: Is your knowledge of the Red Planet out of this world?

Scientists know that Mars spins a little faster each year, but the cause has been a mystery. Now, a new study published Feb. 18 in the Journal of Geophysical Research: Planets suggests the reason may lie deep underground, where a huge plume of buoyant rock could be stirring beneath the Red Planet's crust.

This strange plume could help to explain not just Mars' quicker rotation but also how the planet holds on to geologic heat far longer than expected — forcing scientists to rethink how small, rocky worlds cool and die.

"The Martian surface is so old and shows all these complex but largely not well understood process[es], which I think we can start to unravel by combining interior with surface," Bart Root, an assistant professor of planetary exploration at the Delft University of Technology in the Netherlands and first author of the study, told Live Science in an email. "Understanding Mars will help in understanding our solar system, as its history is laid out on the red soil."

Looking under the surface

Mars has some of the largest volcanoes and mountains in the solar system. This is because, unlike Earth, Mars does not seem to have plate tectonics, the shifting crustal plates that drive much of our planet's volcanic activity. Instead, the lava from Mars' ancient active volcanoes just sits there, piling up and building far bigger structures over time. This resulted in the formation of the Tharsis volcanic province, a volcano-strewn region that stretches 3,700 miles (6,000 kilometers) across the planet's surface.

In 2018, NASA sent the InSight lander to the Red Planet to better understand the planet's interior, which, in turn, could help reveal more about its volcanoes. For years, the lander studied Mars' interior, giving scientists a direct estimate of the crust's thickness.

Using data from InSight, Root and the team ran computer simulations to test what kinds of structures could explain why the volcanic region has dominated one side of Mars. Those models pointed to a plume of unusually light material — called a "negative mass anomaly," or something less dense than the rock that surrounds it — in the mantle beneath the Tharsis region.

According to the researchers, this anomaly may explain how the Tharsis region became so large and full of volcanoes. It could also signal that fresh volcanic activity on Mars may be possible in the future.

"The negative or light mass anomaly will move upwards and hit the lithosphere of Mars, introducing melt pockets that have the potential to penetrate the crust and erupt as volcanoes," Root said. (The lithosphere is a single rigid outer shell approximately 310 miles (500 km) thick.

A solution to spin?

The researchers then asked whether that same hidden plume of material could also explain Mars' strange spin rate. Earlier measurements comparing data from the Viking landers, which explored Mars in the 1970s, with data from InSight showed that Mars' day is shrinking by roughly 70 microseconds per year. That means the planet is rotating slightly faster over time.

Root and his team used their simulations to calculate whether this less-dense material underneath Tharsis could shift mass inside Mars enough to influence the planet's spin.

"With some simple back-on-the-envelope calculations, we can explain the order of magnitude of the observed speed up," Root said. "Of course more complicated modeling will be needed to actually link this better."

Root compared this process to someone spinning in a desk chair while holding heavy books. If the books are pulled inward, the spin speeds up. Mars may be doing something similar with this less-dense material.

"A negative mass flowing upwards means something heavier needs to go down, and because the mass anomaly is located on the equator of Mars, this means the heavier mass is going closer to [the] rotation axis, hence a speed up," Root said.

Besides being a possible solution to some of Mars' biggest mysteries, these models could help scientists better understand how rocky planets cool and eventually die. Mars is much smaller than Earth, so researchers have long assumed it lost its internal heat relatively quickly. But if the Red Planet still has enough energy to drive deep mantle motion, that suggests smaller worlds may stay active longer than expected.

"I would love to show that Mars is more interesting than was assumed," Root said.

Editor's note: This article was updated on Mar. 25 to make clear there isn't currently an active volcano on Mars, as a previous headline suggested. The new discovery hints that fresh volcanic eruptions may be possible in the future, and that Mars is not volcanically dead after all.

Mars quiz: Is your knowledge of the Red Planet out of this world?

Astronomers think they've glimpsed one of the rarest sights in space: two planets smashing into each other around a distant star.

The collision appears to have unfolded roughly 11,000 light-years from Earth, around a sunlike star called Gaia20ehk, near the constellation Puppis (the "poop deck"). The researchers say the crash may echo the giant impact thought to have formed Earth and the moon billions of years ago, giving scientists a rare window into how celestial bodies take shape. The findings were published March 11 in The Astrophysical Journal Letters.

"It's incredible that various telescopes caught this impact in real time," lead study author Anastasios Tzanidakis, a doctoral candidate in astronomy at the University of Washington, said in a statement. "There are only a few other planetary collisions of any kind on record, and none that bear so many similarities to the impact that created the Earth and moon."

A star that suddenly "went completely bonkers"

Planetary collisions are thought to be common in young star systems, but they are hard to catch. The planets must have orbits that take them directly in front of their home star, so that their debris blocks part of the star's light, which telescopes can detect and measure in both visible and infrared light.

Tzanidakis spotted the first clue while combing through telescope data, including observations made by NASA's SPHEREx mission. In 2016, Gaia20ehk looked like an ordinary, stable star. But about five years later, its light dipped suddenly three times and things quickly turned chaotic.

"Right around 2021, it went completely bonkers," Tzanidakis said. "I can't emphasize enough that stars like our sun don't do that. So when we saw this one, we were like 'Hello, what's going on here?'"

Gaia20ehk's particular changes ‪—‬ short drops in brightness and then chaos ‪—‬ had never been observed before, creating a conundrum for the astronomers.

The first clue to what might be happening came from visible-light data, which showed that something was repeatedly passing in front of the star and blocking part of its light. But visible light alone could not show whether the culprit was just floating dust, a stellar outburst or something far more violent, such as a planet being torn apart by the gravity of a supermassive black hole.

To take a closer look, the team analyzed Gaia20ehk's emission in the infrared spectrum. As the star's visible light dipped and grew messy, its infrared signal surged, showing that while the system got dimmer, it was also getting hotter.

That "could mean that the material blocking the star is hot — so hot that it's glowing in the infrared," Tzanidakis said.

That finding suggested to the team that a collision between two planets, while rare to see, was most likely, as two planetary bodies could throw out hot dust and rock into an orbit that would align with their findings.

The researchers think the planets may not have collided in a single instant. The three early dips of Gaia20ehk could mark grazing encounters as the two bodies spiraled closer together.

"At first, they had a series of grazing impacts, which wouldn't produce a lot of infrared energy," Tzanidakis said. "Then, they had their big catastrophic collision, and the infrared really ramped up."

"Andy's unique work leverages decades of data to find things that are happening slowly — astronomy stories that play out over the course of a decade," senior study author James Davenport, an assistant research professor of astronomy at the University of Washington, said in the statement. "Not many researchers are looking for phenomena in this way, which means that all kinds of discoveries are potentially up for grabs."

The team hopes the powerful Simonyi Survey Telescope at the Vera C. Rubin Observatory could be used to discover other planetary collisions that may be difficult to spot. Davenport estimates that, using Rubin, astronomers could discover 100 new impacts over the next decade. Finding other planetary collisions could aid the search for possible habitable worlds that, like Earth, have a moon that helps shield them from asteroids, influences their tides and has other factors that make the world more welcoming.

In addition to being rare, the discovery could provide insight into the type of crash that made our moon. Astronomers said the debris cloud around Gaia20ehk sits at about one astronomical unit from its star — roughly the same distance as Earth orbits the sun — and that is one reason the event resembles the giant impact that struck Earth around 4.5 billion years ago.

If that comparison holds, the system could help researchers further test the theory that a planetary collision created our moon.

"How rare is the event that created the Earth and moon? That question is fundamental to astrobiology," Davenport said. "Right now, we don't know how common these dynamics are. But if we catch more of these collisions, we'll start to figure it out."

Moon quiz: What do you know about our nearest celestial neighbor?

Scientists have found a potential shortcut for identifying stars that host planets. The technique, based on specific signals in starlight, could make it easier to search for exoplanets, according to a new study.

The team has already used their new method to turn up half a dozen previously undiscovered planets — but because most of the alien worlds are very close to their stars, they are unlikely to be habitable, the study authors say.

Many of the 6,000-plus known exoplanets are located extremely close to their host stars. This proximity often doesn't turn out well for such close-in worlds, whose surfaces get whipped up by the stars' intense radiation and form comet-like tails of debris. This includes exoplanets like K2-22b, which was analyzed by the James Webb Space Telescope in 2025. The debris typically remains, for millions of years, as a cloud circling the planet's host star.

But this clutter could help astronomers pinpoint stars that host undiscovered exoplanets orbiting close to their stars. That's because the debris, which is mainly a mixture of different gases, absorbs some of its parent star's light at specific visible frequencies.

"That absorption could make the star appear artificially [magnetically] less active," Matthew Standing, a research fellow at the European Space Agency's European Space Astronomy Centre in Madrid and the new study's lead author, told Live Science via email. In other words, magnetically inactive stars are potentially good targets in the search for crumbling, close-in exoplanets.

If this hypothesis is confirmed, it could make planet-searching ventures less random.

Signals from the stars

To test the idea, Standing and an international team of collaborators first identified a set of 24 stars with apparently low magnetic activity as part of the Dispersed Matter Planet Project (DMPP), including a handful of stars that the DMPP had analyzed in 2020. The researchers then collected visible-light spectra — the light curves that correspond to wavelengths of electromagnetic radiation that humans can see — from these stars, using telescopes at the European Space Observatory in Chile.

They observed each star at least 10 times for up to two weeks. If a star hosted one or more planets, its gravitational "tugs" on its star would cause it to wobble, which would be visible in the spectra. (This method of identifying exoplanets is called the radial-velocity technique.)

Next, the team used a computational algorithm to determine if such changes in the light curves could correspond to as many as four planets for each star system. The analysis also allowed the researchers to determine how sensitive the survey was and how common close-in planets are around stars with low magnetic activity levels.

The results, published Feb. 28 in the journal Monthly Notices of the Royal Astronomical Society, showed that 14 stars hosted a total of 24 exoplanets, including a total of seven newly discovered worlds in five of these systems.

The team also calculated that the occurrence of exoplanets around the stars they selected was between eight and 10 times higher than in other radial-velocity surveys. This occurrence rate supports the hypothesis that stars that seem magnetically inactive are likely hosts of close-in, highly irradiated exoplanets.

Additionally, the researchers found that the survey was very comprehensive, identifying nearly 95% of exoplanets that were more than 10 times as massive as Earth and orbited their host stars in five days or less.

The team also extrapolated their results to our cosmic neighborhood, curating a list of roughly 16,000 stars lying within 1,600 light-years from the solar system. (For reference, a light-year is the distance light travels in a year — approximately 5.88 trillion miles, or 9.46 trillion kilometers.) From this list, the researchers found 241 stars with similar signatures of low magnetic activity. Given the proportion of exoplanets in the study, they estimate that these stars may host around 300 planets, just waiting to be discovered.

Standing is cautiously enthusiastic about the technique's potential. "If confirmed with larger samples, this method could help make exoplanet searches more efficient," he said.

The team plans to do just that, expanding the size of their sample and continuing to monitor radial-velocity data for signs of planets, he added.

Organic molecules discovered within a stone on Mars cannot be fully explained by nonbiological processes, and it's "reasonable to hypothesize" that living things could have formed these odd organic molecules, a NASA-led team reports in a new study. However, this doesn't mean scientists have found definitive proof of life on Mars, they cautioned.

In March 2025, scientists reported the discovery of the largest organic molecules ever found on Mars. These long chains made of hydrogen and carbon may be the fragments of fatty acids, which are often created through biological processes.

In a paper published Feb. 4 in the journal Astrobiology, researchers analyzed numerous ways those organic molecules could have formed. Using mathematical modeling, information from the Curiosity rover, and data from recent radiolysis experiments, which assess how molecules are destroyed by radiation, the researchers rewound the clock by billions of years to extrapolate how abundant the molecules may have been when they were first deposited.

A discovery more than a decade in the making

The organic molecules in question are called alkanes. They are hydrocarbons, long chains of 10 to 12 carbon atoms with multiple hydrogen atoms attached to each carbon. If the ending of their names sounds vaguely familiar, it’s because the alkane chemical family includes ethane, methane, propane and butane — though these are much shorter chains. Alkane chains of 12 carbons or more are more likely to be made by biological processes.

These tantalizingly large molecules are embedded within the Cumberland mudstone, a fine-grained sedimentary rock in an ancient Martian lake bed named Yellowknife Bay. Curiosity initially drilled into this stone back in 2013 and has since performed various analyses using its onboard chemistry lab, the Sample Analysis at Mars instrument.

However, researchers discovered the organic molecules only around a year ago, after preheating the sample to 2,012 degrees Fahrenheit (1,100 degrees Celsius) in a search for amino acids. Instead of the building blocks of proteins, however, they found the traces of the largest organic molecules ever discovered on Mars.

Rewinding the clock on a Martian mudstone

In the recent study, researchers wound back the clock on this sample, extrapolating how abundant these molecules would have been billions of years ago when they were deposited in the mudstone.

The alkanes in the sample have a measured abundance of 30 to 50 parts per billion (ppb), but the Cumberland mudstone has been exposed to the harsh effects of radiation on Mars' surface for about 80 million years. As a result, its organics have been degraded by the eons-long bombardment of energetic particles from the sun and from the universe at large.

"Given the geologic history and thermal maturation of the organics preserved in the Cumberland sample, it is reasonable to presume that the recovered material is only a fraction (possibly several orders of magnitude less) of the primary lipid content that would have been entrained in the sedimentary unit when it was deposited two and a half billion years ago," the researchers explained in the paper.

Using previous radiolysis experiments as a gauge, the researchers calculated a "conservative" initial abundance of 120 to 7,700 ppb for the alkanes, or the fatty acids from which they fragmented. So, could abiotic sources account for substantial quantities of these substances, or did they form through biological processes?

The researchers assessed numerous scenarios. First, they explored a space-based origin. Interplanetary dust particles (IDPs) and meteorites frequently deliver organic molecules to the Martian surface. But the researchers concluded that it is unlikely that these processes account for the organic abundance in the Cumberland sample because IDPs cannot penetrate rock and there are no signs of meteorite impacts.

In the second scenario, organic molecules settle on the surface after separating from the atmosphere, but Mars' ancient atmospheric haze wasn't foggy enough to explain the observed abundance.

Water-rock interactions could have contributed, but they generally produce smaller organic molecules. Fatty acid molecules can occur via a different pathway; but it requires high temperatures, and Cumberland shows no signs of having been appropriately heated.

Proof of alien life?

Despite these ruled-out theories, one non-biological process did hold water: the researchers cannot rule out that some of the organics formed abiotically in Mars' hydrothermal systems and were transported to the surface by watery, organic-rich fluids.

"To be clear, we do not claim that proof of ancient martian life was found in the Cumberland mudstone," the researchers said in the paper.

Still, the Cumberland sample is rich in many biologically implicated molecular goodies. These include clay minerals that form in the presence of water, nutritious nitrates, a type of carbon linked with biological processes, and the sulfur that helps preserve organic molecules.

Gale Crater, the site of Yellowknife Bay, also held water for untold millions of years, ostensibly giving life-forming chemistry plenty of time to mix and match a multitude of molecules.

Yet the Curiosity rover may be limited in its ability to analyze even larger molecules — which are more likely to be associated with biological processes — because of the way it must separate and identify them. Analyses like these, even on Earth, "always have tradeoffs," study co-author Christopher House, geosciences professor at Penn State College of Earth and Mineral Sciences, told Live Science via email. "So, Curiosity might be able to find larger organic molecules, but not with the [precision] that made the identification of these specific molecules convincing."

The next step is to perform experimental studies on Earth that mimic the Cumberland mudstone and the Martian environment, in order to ascertain how organic molecules like fatty acids react to Martian conditions. (The ultimate goal is for scientists to get their hands on some real Martian mudstone via a Mars sample-return mission, though that is currently a murky proposition at best.)

The existence of past or present Martian life is also hazy, but there's reason for optimism among ET aficionados. The "researchers say that as the non-biological sources they considered could not fully explain the abundance of organic compounds, it is therefore reasonable to hypothesize that living things could have formed them," NASA officials said in a statement.

Coincidentally, the microbial processes that could have produced these organics may have emerged on Earth around the same time, during the Archean eon. Considering that the Perseverance rover also discovered potential biosignatures in 2025, the answer to the ultimate question is more beguiling than ever.

NASA's Curiosity rover has snapped stunning new photos of giant "spiderwebs" zig-zagging across the surface of Mars. One of these images has revealed never-before-seen, egg-like spheroids covering the sprawling structures — and scientists are struggling to explain them.

Over the last 8 months, Curiosity has been closely examining a series of interconnected rocky ridges, dubbed "boxwork," on the slopes of Mount Sharp, in the Gale Crater. These ridges, which cover an area up to 12 miles (20 kilometers) across, were created billions of yars ago as ancient Martian groundwater seeped beneath the planet's surface. They were first spotted by orbital spacecraft in 2006, but they have remained largely unexplored until now.

The web-like structures should not be confused with the infamous "spiders on Mars" — a series of geological features that are created when carbon dioxide ice sublimates beneath the Red Planet's surface and look like swarming arachnids when viewed from above. (These faux spiders were also recently recreated on Earth, while a similar "wall demon" was also spotted on Jupiter's moon Europa.)

NASA released Curiosity's first boxwork photos in June 2025, shortly after reaching the rocky ridges. But on Monday (Feb. 23), the agency released two more snaps, which showed the structures in much greater detail.

One of these photos, captured Sept. 26 last year, shows off a ground-level view of the ridges, which stand 3 to 6 feet (1 to 2 meters) above Mars' surface. But a second close-up image, snapped on Aug. 21, revealed that some of these ridges are covered in tiny irregular-shaped lumps, or nodules, that have not been seen until now.

These nodules bear a striking resemblance to mini spheroids on the surface of a mysterious "spider egg" rock, which was discovered in the Jezero Crater by NASA's Perseverance rover last year and has an unknown origin. And researchers are also having a hard time explaining exactly how the tiny boxwork "eggs" formed.

"We can't quite explain yet why the nodules appear where they do," Tina Seeger, a planetary scientist at Rice University in Houston who is leading Curiosity's boxwork investigations, said in a statement. "Maybe the ridges were cemented by minerals first, and later episodes of groundwater left nodules around them," Seeger said. But more work is needed to confirm if this is the case.

However, while the nodules and boxwork have an eerily biological appearance, there is no suggestion that they have any direct ties to extraterrestrial life.

Martian spiderwebs

Boxwork is made up of criss-crossing ridges of mineral-rich rocks that litter the surface of Mars. Similar yet smaller structures are found on Earth, predominantly within caves, and form when calcite-rich water flows between rocks that are eventually eroded, much like how stalagmites and stalactites form, according to the National Speleological Society.

However, on Mars, the boxwork was shaped by the fierce winds that scour the planet's surface: "The bedrock below these ridges likely formed when groundwater trickling through the rock left behind minerals that accumulated in those cracks and fissures, hardening and becoming cementlike," NASA representatives previously wrote. "Eons of sandblasting by Martian wind wore away the rock but not the minerals, revealing networks of resistant ridges within."

The team is particularly interested in the patch of boxwork on Mount Sharp because it formed in isolation and is surprisingly high up the mountain's slopes, which has implications for the planet's puzzling watery past.

"Seeing boxwork this far up the mountain suggests the groundwater table had to be pretty high," Seeger said. This hints that the water in this area may have "lasted much longer than we thought," she added.

Researchers hope that further investigation will also shed light on the specific conditions that formed these structures and whether they might have been favorable to any potential ancient Martian microbes.

"These ridges will include minerals that crystallized underground, where it would have been warmer, with salty liquid water flowing through," Kirsten Siebach, a Curiosity mission scientist at Rice University who has also studied the area, previously said. "Early Earth microbes could have survived in a similar environment. That makes this an exciting place to explore."

Uneven terrain

While the latest stage of Curiosity's mission is yielding fascinating results, it is also proving to be one of the hardest to navigate.

The boxwork is arguably the hardest terrain that the car-sized robot has had to traverse since it landed in the Gale Crater in 2012. The rover must balance along the ridges "like a highway" and avoid slipping "down into the hollows" between them, Ashley Stroupe, a systems engineer at NASA's Jet Propulsion Laboratory in Southern California, said in the statement.

The task of controlling the rover has also become increasingly challenging due to a gaping hole in one of the robot's wheels, which was first spotted in late 2024.

"There’s always a solution," Stroupe said. "It just takes trying different paths."

Mars quiz: Is your knowledge of the Red Planet out of this world?

Scientists using the James Webb Space Telescope just mapped the mysterious upper atmosphere of Uranus for the first time, revealing strange new features of the planet's mysterious magnetic field and glowing auroras.

The James Webb Space Telescope (JWST) observed Uranus rotating for 15 hours (nearly a full Uranian day) to learn more about how ice giants distribute energy in the upper layers of their atmospheres and to investigate how the planet's auroras operate.

Uranus' magnetic field is unique among the big planets of our solar system in that its magnetic pole is tilted by 60 degrees relative to its geographic pole. That tilt produces auroras that extend far beyond the poles of Uranus, unlike auroras on Earth.

To learn more, scientists used JWST to study Uranus' magnetosphere — the region of space around Uranus that's dominated by the planet's magnetic field.

"Uranus's magnetosphere is one of the strangest in the solar system," study lead author Paola Tiranti, a doctoral student at Northumbria University in the U.K., said in a European Space Agency (ESA) statement. "Webb has now shown us how deeply those effects reach into the atmosphere."

Strange lights on Uranus

JWST charted "the most detailed portrait yet" of how particles in Uranus' upper atmosphere are energized (ionized) by interactions with the sun, ESA officials said in the statement. The study, published Feb. 19 in the journal Geophysical Research Letters, aimed to measure ion temperature and density as far as 3,100 miles (5,000 kilometers) above the cloud tops of Uranus.

Temperature and density do not peak at the same altitude, JWST showed. Ions were the warmest between roughly 2,500 and 3,100 miles (4,000 and 5,000 km) but the densest at about 600 miles (1,000 km). This is because of the "complex geometry" of the planet's magnetic field, ESA officials said in the statement.

That geometry also produced two bright bands of auroras near Uranus' magnetic poles. In between the aurora belts, however, there is a "depletion" in both ion density and auroral emissions — an effect likely produced by transitions between the planet's magnetic-field lines, the scientists said. Observations at Jupiter's upper atmosphere have shown similar transition regions.

In addition to charting Uranus' upper atmosphere in three dimensions for the first time, JWST confirmed findings from previous studies that suggested the planet's upper atmosphere has been cooling steadily since the early 1990s. The telescope showed the average temperature of Uranus' atmosphere is about 307 degrees Fahrenheit (153 degrees Celsius), which is lower than the temperature measurements from other spacecraft and ground-based telescopes.

"By revealing Uranus's vertical structure in such detail, Webb is helping us understand the energy balance of the ice giants," Tiranti said. "This is a crucial step towards characterizing giant planets beyond our solar system."

James Webb Space Telescope quiz: How well do you know the world's most powerful telescope?

A planetary parade is about to bring six of Earth's neighbors into the night sky at once — but it won't be easy to see.

If you can find an unobstructed view due west and clear skies on Saturday, Feb. 28, you may see the two inner planets, Venus and Mercury, close to Saturn, with Neptune, Uranus and Jupiter also in the night sky, according to NASA.

The window will be tight, with Venus, Mercury, Saturn and Neptune appearing only briefly after sunset. Venus, Mercury and Saturn should all be visible to the naked eye, though a pair of stargazing binoculars may be helpful. Venus and Mercury will be closest to the horizon during twilight, with Saturn above.

Neptune will be right next to Saturn, but a 6-inch (15 centimeters) skywatching telescope will be required to get a good view of Neptune (and, in twilight, even that's unlikely). These four planets will be in the sky about half an hour after sunset and remain so for around 45 minutes.

Once you've observed Venus, Mercury, Saturn and Neptune, look high in the south for Jupiter in the constellation Gemini. It will shine very brightly, so it should be easy to find. The three stars of Orion's Belt will be roughly halfway between the other four planets and Jupiter. The giant planet will also appear as a steady, whitish light that doesn't twinkle as stars do.

Uranus, the Pleiades and a total lunar eclipse

The seventh planet, Uranus, will also be in the night sky, but it will be best seen with binoculars or a small telescope. To find it, use Orion's Belt again, following its three stars — Alnitak, Alnilam and Mintaka — upward, until you get to the shimmering sight of the Pleiades open cluster (also called "The Seven Sisters" or M45). Uranus will be just below the Pleiades, in the constellation Taurus.

As a bonus, on Feb. 28, the moon will also be in the night sky alongside another famous star cluster. About 92%-illuminated, the waxing gibbous moon will move close to the Beehive Cluster (also called M44 and NGC 2632), a bright cluster of around 1,000 stars that's about 577 light-years from the solar system.

As the planetary parade fades, something arguably more spectacular takes its place: a total lunar eclipse on March 3 as the full "Worm Moon" passes through Earth's dark shadow. During this event, also dubbed a "blood moon," the lunar surface will turn a reddish-copper color for 58 minutes, with the best views of the entire eclipse sequence from the western U.S. (including Alaska and Hawaii), the Pacific islands, New Zealand, Australia and East Asia.

Saturn's largest moon, Titan, may be made of two different moons that smashed together hundreds of millions of years ago, a new study suggests. If confirmed, this epic collision could also help to solve several long-standing mysteries surrounding the gas giant, including how its iconic rings formed.

Titan is the solar system's second-largest moon, behind Jupiter's Ganymede. It is around 3,200 miles (5,150 kilometers) across, which is roughly 1.5 times wider than Earth's moon and around 5% wider than Mercury.

Aside from its immense size, Titan is notable for its dense atmosphere, which consists mainly of nitrogen and is around 1.5 times thicker than Earth's atmosphere. It is also the only solar system body, other than Earth, that has confirmed liquid on its surface, in the form of methane — making it a potential candidate for hosting extraterrestrial life. The European Space Agency's Huygens probe touched down on Titan in 2005, making it the only moon, other than our own, that a spacecraft has landed on.

Until now, researchers thought that, like most other moons, Titan formed billions of years ago via the gradual accumulation of tiny chunks of rock and dust. But in the new study, uploaded Feb. 9 to the preprint server arXiv and accepted for future publication in The Planetary Science Journal, researchers from the SETI Institute showed that this may not be the case.

Based on data collected by NASA's Cassini probe, which flew past Titan and deployed Huygens to its surface, the SETI team proposes that Titan may have formed around 400 million years ago when two similarly massive moons slammed into each other.

This collision also may have birthed another Saturnian moon, Hyperion, the researchers argue. This smaller satellite, which is around 84 miles (135 km) wide, likely formed from the debris from the collision, much like Earth's moon did when the protoplanet Theia smashed into Earth around 4.5 billion years ago.

Additionally, the new hypothesis may explain the unusual orbits of several other Saturnian satellites, the team said.

Saturn's missing moon

Saturn has at least 274 moons — the most of any planet — after the recent discovery of 128 natural satellites. However, researchers have long suspected that another massive moon is missing.

Saturn's orbit around the sun is heavily tilted relative to the rest of the planets (excluding its wonky neighbor Uranus), which not only allows us to see the planet's extraordinary rings but also hints that something massive once pulled it out of place. This mystery object was most likely a large moon, which researchers have long suspected was gravitationally slingshotted away from Saturn.

In the new study, researchers explored the possibility that this moon didn't disappear but was instead destroyed.

The "most important clue" that this other moon was destroyed is Hyperion, which is locked in an orbital resonance with Titan, circling Saturn three times for every four of Titan's orbits.

"We recognized that the Titan-Hyperion lock is relatively young, only a few hundred million years old," study lead author and SETI researcher Matija Ćuk said in a statement. "This dates to about the same period when the extra moon disappeared. [So] perhaps Hyperion did not survive this upheaval but resulted from it."

After simulating multiple scenarios from the Cassini data, the team now thinks two massive moons, dubbed "Proto-Titan" and "Proto-Hyperion," smashed into each other, thereby birthing Titan and eventually creating Hyperion from the remnants of the massive collision.

Rings, orbits and automobiles

Hyperion may not have been the only moon created or affected by this potential crash.

The researchers propose that the impact could have birthed several other moons that slowly drifted toward Saturn and collided with other existing satellites, creating a field of debris that eventually settled into Saturn's rings around 100 million years ago. (This hypothesis contradicts a recent study that suggested Saturn's rings are much older than previously realized.)

The study team also theorizes that the collision could explain the wonky orbits of two other Saturnian moons, Iapetus and Rhea, which are significantly tilted compared with their surrounding satellites and somewhat resonate with Titan's orbit.

In addition, their hypothesis could explain Titan's surprising lack of impact craters: Because it is much younger than previously realized, it has been exposed to fewer meteor strikes. The team proposes that, prior to its creation, Proto-Titan may have been covered in pockmarks, similar to Jupiter's moon Callisto.

NASA is preparing to send its Dragonfly probe to visit and explore Titan. The drone-like spacecraft is scheduled to launch in 2028, which would allow it to reach the moon by 2034. When it arrives, it could potentially confirm the collision hypothesis and unravel more of the moon's remaining mysteries.

Planets go through different life stages: They form, evolve and eventually meet an end. But the timelines for these processes differ widely between Earth-like planets and worlds that orbit less-powerful stars.

So, how long do most planets last?

First, it's important to understand the life cycles of planets.

"Planets start off as microscopic dust grains in disks orbiting young stars, and eventually grow by a huge amount through a series of collisions," Sean Raymond, an astrophysicist at the University of Bordeaux in France, told Live Science in an email.

Gas giants, like Jupiter and Saturn, start off as massive rocky and icy cores, and then capture gas from the disk to become giants. Rocky planets like Earth undergo a late phase of giant collisions with other growing planets and smaller objects after the gas disk from the sun had dissipated, Raymond said. However, there is still some debate among scientists about the order in which planets formed.

Defining the "end" of a planet, however, is more complicated. "You could say a planet lasts until it's destroyed," Matthew Reinhold, a planetary scientist at Stanford University, told Live Science. Or, you could define a planet's ending to be when it no longer operates under the same conditions. "You could say, 'This was a world that had these conditions at some point, but now it has changed and has these very different conditions," Reinhold said. "Because I prefer those previous conditions; I consider this planet as having ended.'"

Let's take Earth as an example. Like many others, our planet's lifespan is tied to the evolution of the sun. The sun currently creates heat and light through nuclear fusion at its core — a process in which hydrogen transforms into helium. In about 5 billion years, the sun will run out of hydrogen, at which point it will expand into a red giant and eventually collapse into itself.

"Our Earth will 'die' in multiple ways," Raymond said. "First, the slowly-brightening Sun will make conditions on the Earth unlivable by vaporizing the oceans. Then, Earth may be swallowed by the Sun when it becomes a red giant. Finally, Earth (if it's still around) will be tossed into interstellar space."

According to these calculations, Earth's total lifespan will be about 9.5 billion years.

Earth probably won't live as long as most planets, he noted. That's because, unlike the sun, which is a yellow dwarf star, most stars are red dwarfs that are smaller and cooler than our sun, and they burn fuel much more slowly. "They can last for trillions of years," Reinhold said.

In that case, it might not be the death of the star, but rather an internal process that leads to these planets' demise.

In his work, Reinhold has modeled what might happen to a hypothetical habitable planet orbiting a red dwarf star. Active geology, such as plate tectonics, is considered crucial for habitability because it allows nutrients to move between the planet's mantle and surface and drives the carbon-silicate cycle.

"We want a planet that can stabilize its climate," Reinhold said, and the carbon-silicate cycle is Earth's natural thermostat.

Reinhold found that mantle convection will last somewhere between 30 billion and 90 billion years, while mantle melting might last somewhere between 16 billion and 23 billion years. Although these number ranges are too large to be meaningful, Reinhold said, they suggest that any Earth-like planets orbiting a red dwarf will die of an internal process long before their stars get close to the ends of their lives. And even on the shortest timelines, most rocky planets orbiting red dwarfs will maintain their conditions for billions of years.

Bigger stars have much shorter lifespans, because they use up their nuclear fuel more quickly. So the fate of an inner planet orbiting an A-type white star, for instance, would be tied up to the star's lifespan of 100 million to 1 billion years.

It's also possible for gas giants to lose their atmospheres due to the intense light from their star, Reinhold said, becoming rocky planets. This process depends on how close a planet is to its star, how much energetic radiation the star emits, and how strong a planet's gravity is. "The stronger their gravity, the better they are at holding onto their atmospheres, and the more radiation they get from their star, the more intense the stripping power," Reinhold explained. Depending on those factors, this can take anywhere from millions to billions of years.

The end of the universe

Even when a planet's conditions change over time, the rock itself still exists. But over large timescales, there are different possibilities for its fate as the probability of rare events increases. It may collide with another planet, or be kicked out of its orbit.

"In all of this mayhem over quadrillions of years, the planets that have been kicked away from their stars will be kicked out of the galaxy to wander for eternity in the void," Reinhold said. "What actually seals [its] fate really comes down to the nature of the end of the universe," said Reinhold.

Solar system quiz: How well do you know our cosmic neighborhood?

Astronomers have spotted an unusual planetary system with a rebellious rocky planet orbiting well beyond where it would be expected to form.

Typically, rocky planets develop closer to a star, and gaseous planets form farther out — as is the case in our solar system, with a vast asteroid belt drawing the line between rocky Mars and gassy Jupiter.

And in the newly spotted system of four planets, the first three follow this pattern. But the system also has a rocky planet orbiting at its outer edge, beyond the two gas planets. That suggests the planet formed after the gas in the protoplanetary disk was already used up, researchers reported Feb. 12 in the journal Science.

"This strange disorder makes it a unique inside-out system," study co-author Thomas Wilson, an exoplanet scientist at the University of Warwick in the U.K., said in a statement. "Rocky planets don't usually form far away from their home star, on the outside of the gaseous worlds."

A rebel world

As the planets in our solar system formed and grew, they accreted dust, metals and other solids. Far from the sun, materials such as water and methane remained solid due to the cooler temperatures. As the outer planets got larger, they pulled in hydrogen and helium from their surroundings and grew into gas giants.

"Historically, our planet formation theories are based on what we see and know about our Solar System," study co-author Isabel Rebollido, a researcher who studies exoplanet systems at the European Space Agency (ESA), said in the statement. "As we are seeing more and more different exoplanet systems, we are starting to revisit these theories."

In the new study, Wilson and colleagues searched for exoplanets surrounding the red dwarf star LHS 1903, which had been observed by the Transiting Exoplanet Survey Satellite between 2019 and 2023. When a planet passes between the star and the satellite, it dims the star's light slightly. Then, they studied the properties of those planets, using the Characterizing Exoplanets Satellite (CHEOPS).

The scientists spotted four exoplanets orbiting the star, including the distant rocky one. The planets likely did not form at the same time, the team found; instead, they developed one by one and changed the environment in which each subsequent planet grew.

"By the time this final outer planet formed, the system may have already run out of gas, which is considered vital for planet formation," Wilson said in the statement. "Yet here is a small, rocky world, defying expectations. It seems that we have found [the] first evidence for a planet that formed in a gas-depleted environment."

The team further ruled out ideas that the distant rocky planet had lost its atmosphere in a collision or swapped places with a gas planet.

"Much about how planets form and evolve is still a mystery," study co-author Maximilian Günther, an astrophysicist at ESA, said in the statement. "Finding clues like this one for solving this puzzle is precisely what CHEOPS set out to do."

Scientists may have solved a long-standing mystery surrounding Uranus' extraordinarily strong radiation belt.

A new analysis of Voyager 2 data suggests that a temporary space weather event may have made the planet's electron radiation belt more intense than usual as Voyager 2 was passing by. The findings could help to explain why the radiation belt was so much stronger than scientists had predicted it would be.

Radiation belts are formed from interactions between the solar wind and a planet's magnetic field. The sun emits a continuous stream of protons and electrons from its outer atmosphere, called the corona. For planets that have a global magnetic field, including Earth and Uranus, some of those energetic, charged particles get trapped in the magnetosphere.

In January 1986, Voyager 2 flew by Uranus and measured the strength of its radiation belts. While the ion radiation belt was a little weaker than expected, the electron radiation belt was much more intense than scientists had predicted — close to the maximum intensity Uranus could sustain. Since then, scientists have tried to figure out how and why this was the case.

"Science has come a long way since the Voyager 2 flyby," Robert Allen, a space physicist at the Southwest Research Institute (SwRI) and coauthor of the new research, said in a statement. "We decided to take a comparative approach looking at the Voyager 2 data and compare it to Earth observations we've made in the decades since."

Earth versus Uranus

In the study, published in November 2025 in the journal Geophysical Research Letters, Allen and colleagues revisited data collected by Voyager 2 during its flyby of Uranus. They found several similarities between the Voyager data and the data collected from Earth orbit during a space weather event in 2019.

Uranus' unusually intense radiation belt may have been caused by a "co-rotating interaction region," the team found. A co-rotating interaction region occurs when high-speed solar winds overtake slower solar wind streams. The phenomenon could have accelerated electrons and added energy to the radiation belt, the researchers said.

"In 2019, Earth experienced one of these events, which caused an immense amount of radiation belt electron acceleration," said study co-author Sarah Vines, a space physicist at SwRI. "If a similar mechanism interacted with the Uranian system, it would explain why Voyager 2 saw all this unexpected additional energy."

If that's the case, it raises many more questions about the physics of Uranus' magnetosphere and its interactions with the solar wind, including the radiation belt's stability during the extreme seasons caused by the planet's tilted axis of rotation. A spacecraft orbiting Uranus and collecting data from different parts of the magnetosphere could help address those questions, the researchers wrote in the study.

"This is just one more reason to send a mission targeting Uranus," Allen said in the statement. "The findings have some important implications for similar systems, such as Neptune's."

Many tiny specks of ancient water are locked within one of the oldest and most famous Martian meteorites ever to fall to Earth, a new study finds. The surprising discovery, achieved using a new form of "neutron scanning," reveals more clues about the Red Planet's watery past, which may have set the stage for extraterrestrial life to flourish.

Meteorite NWA 7034, more commonly known as Black Beauty, is a roughly 11-ounce (320 grams) chunk of Mars that was ejected when another space rock slammed into the Red Planet. It was discovered in 2011 by nomads in the Moroccan region of the Sahara Desert, although it is unclear when it fell to Earth. The meteorite has since become famous for its dark hue, which has been further accentuated by heavy polishing on one of its faces.

Black Beauty likely originates from the 6-mile-wide (10 kilometers) Karratha crater near Mars' equator, and was ejected into space between 5 million and 10 million years ago, according to Live Science's sister site Space.com. However, it is much older than that, and scientists have since dated the coal-like rock to at least 4.44 billion years ago, making it the oldest Martian meteorite found to date.

Researchers have known since 2013 that Black Beauty contained traces of water. More recent analyses of the meteorite have revealed evidence that this water may have been partially heated, raising hopes that Martian microbes may have once thrived in warm waters on the Red Planet.

Until now, however, researchers have had to break off and destroy tiny chunks of the meteorite to properly study the water trapped within it, which has limited what they can learn from it, according to Universe Today.

But in the new study, uploaded Jan. 13 to the preprint server arXiv, researchers report that a new scanning method has allowed them to create the first in-depth analysis of the meteorite's entire water content.

This examination revealed that water likely accounts for around 0.6% of Black Beauty's mass, which equates to a piece of the rock around the size of a human fingernail, according to Universe Today. This may not sound like much, but it is much more than previous estimates had suggested.

Most of this water is locked within tiny fragments, or clasts, of hydrogen-rich iron oxyhydroxide (FeHO₂), which is similar to the main component of rust and forms when iron reacts with water under high pressure, like during a meteor impact.

In the new study, researchers used a version of CT scanning, which builds an internal image of soft objects, like the human body, using X-rays. But instead of using electromagnetic radiation, the team bombarded the meteorite with neutrons, which proved to be particularly good at identifying hydrogen atoms embedded within the extremely dense sample.

You can see this process in action for yourself in a YouTube video shared by one of the researchers.

Water on Mars

It is hard to imagine that the dusty red ball Mars is today was once a water world. However, a mounting body of evidence suggests the planet was once home to large, Earth-like oceans until around 3 billion years ago.

Most of this water has since disappeared, although some of it remains in the form of ice slabs buried near the planet's equator, frosty deposits at the summit of Martian mountains, and a massive subsurface reservoir discovered in 2024.

Black Beauty is widely considered the oldest direct evidence of water on Mars, so it could help reveal how Mars first acquired its once-abundant water. As a result, researchers are keen to further analyze its insides.

Given that NASA recently pulled the plug on its Mars sample-return mission, which would have delivered samples collected by the Perseverance rover back to Earth, meteorites like Black Beauty are the only way to directly study Martian water.

Jupiter's ice-covered moon Europa appears to have life-friendly molecules on its surface.

Al Emran, a researcher with NASA's Jet Propulsion Laboratory, spotted ammonia on the surface of Europa while looking through old data from the Galileo mission, which studied Jupiter and its moons from 1995 to 2003.

Data gathered from Galileo's near-infrared mapping spectrometer in 1997 showed "faint signals of ammonia" near cracks on the frozen moon's surface, NASA officials wrote in a statement describing the findings, which were published late last year in The Planetary Science Journal.

It is the "first such detection at Europa" and therefore has important implications for the habitability of the icy moon, which is considered one of the most likely places in the solar system to host extraterrestrial life, according to the statement.

Alien ice moon

Ammonia is a nitrogen-bearing molecule and one of the ingredients of life as we know it, alongside carbon, hydrogen, oxygen and water. In the new paper, Emran said the finding was therefore of "astrobiological significance, given nitrogen's essential role in the chemistry of life."

The Galileo spacecraft worked in the Jupiter system between 1995 and 2003, before it ran low on fuel. Engineers deliberately steered the spacecraft into the giant planet to avoid any risk of contaminating Europa or other icy moons. Although the mission concluded operations more than 20 years ago, scientists sometimes find new insights in older datasets, either by using newer tools or knowledge, or by examining information that was not previously scrutinized.

In the new research, NASA spotted traces of ammonia near fractures on the icy surface of Europa. It is believed that these fractures included liquid water with ammonia compounds; the ammonia lowers the freezing point of water, sort of like antifreeze, the agency said.

The ammonia may have come "from either the moon's subsurface ocean, or its shallow subsurface," NASA officials said in the statement. That's because ammonia doesn't last long in space because it gets broken down by ultraviolet light and cosmic radiation. Cryovolcanism, or icy volcanism, likely pushed the ammonia compounds to the surface, they explained.

A follow-up mission may reveal more insight: Europa Clipper, which launched in October 2024, is expected to arrive at the Jupiter system in April 2030. The mission will specifically look for chemical signs of habitability on the icy moon.

Jupiter is slightly smaller and flatter than scientists thought for decades, a new study finds.

Researchers used radio data from the Juno spacecraft to refine measurements of the solar system's largest planet. Although the differences between the current and previous measurements are small, they are improving models of Jupiter's interior and of other gas giants like it outside the solar system, the team reported Feb. 2 in the journal Nature Astronomy.

"Textbooks will need to be updated," study co-author Yohai Kaspi, a planetary scientist at the Weizmann Institute of Science in Israel, said in a statement. "The size of Jupiter hasn't changed, of course, but the way we measure it has."

Until now, scientists' understanding of Jupiter's size and shape have been based on six measurements performed by the Voyager 1 and 2 and Pioneer 10 and 11 missions. Those measurements, which have since been adopted as standard, were performed around 50 years ago using radio beams, according to the statement.

But the Juno mission, which has been gathering data on Jupiter and its moons since it arrived at the gas giant in 2016, has collected much more of this radio data in the past two years. With that additional data, researchers have now refined measurements of Jupiter's size down to about 1,300 feet (400 meters) in each direction.

"Just by knowing the distance to Jupiter and watching how it rotates, it's possible to figure out its size and shape," Kaspi said. "But making really accurate measurements calls for more sophisticated methods."

Bending light

In the new study, the scientists tracked how the radio signals from Juno back to Earth bent as they passed through Jupiter's atmosphere, before cutting out when the planet blocked the signal entirely. Those measurements allowed the team to account for Jupiter's winds, which slightly alter the shape of the gaseous planet. Then, they used that information to make precise calculations of the planet's shape and size.

With the new data, the team calculated that the planet's radius from its pole to its center is 41,534 miles (66,842 km) — 7.5 miles (12 km) smaller than previous measurements. The newly calculated radius at the equator is 44,421 miles (71,488 km) — 2.5 miles (4 km) smaller than previously thought.

"These few kilometers matter," study co-author Eli Galanti, an expert on gas giants at the Weizmann Institute of Science, said in the statement. "Shifting the radius by just a little lets our models of Jupiter's interior fit both the gravity data and atmospheric measurements much better."

The updated measurements will improve our understanding of Jupiter's interior, as well as help scientists interpret data from gas giants beyond the solar system, the researchers wrote in the study.

"This research helps us understand how planets form and evolve," Kaspi said in the statement. "Jupiter was likely the first planet to form in the solar system, and by studying what's happening inside it, we get closer to understanding how the solar system, and planets like ours, came to be."

A giant cloud of vaporized metal may be hiding a secret planet or second alien sun in a nearby star system, a new study reveals.

The mysterious cloud is up to 15,000 times wider than our planet, and made its home star almost completely disappear from telescope observations for nearly nine months when the ghostly object oozed between its host star and Earth.

Astronomers were first alerted to the mysterious cloud's presence in September 2024, when they detected a surprise dimming event surrounding the star J0705+0612 (sometimes referred to as ASASSN-24fw) — a sun-like, main sequence star around 3,000 light years from Earth. The star's brightness suddenly fell 40-fold, to around 3% of its original luminosity, and remained that way for just over eight and a half months before returning to full brightness in May 2025.

"Stars like the sun don't just stop shining for no reason," study lead author Nadia Zakamska, an astrophysicist at Johns Hopkins University, said in a statement. "So dramatic dimming events like this are very rare."

In the study, published Jan. 21 in The Astronomical Journal, Zakamska and her team analyzed this strange event using data captured by the Gemini South telescope and the Magellan Telescopes in Chile, and found that a massive object had passed in front of, or occulted, J0705+0612. After ruling out things like giant planets and asteroid belts, which were either too small or too diffuse to block out so much light for so long, the researchers concluded that the occulting object was a thick cloud of molecular gas.

The unnamed cloud is approximately 125 million miles (200 million kilometers) across and is positioned around 13.3 astronomical units (or roughly 13.3 Earth-sun distances) from J0705+0612. For context, that would put it around halfway between Saturn and Uranus if it were located in our solar system. At this distance, it takes about 44 years for the cloud to fully orbit its home star.

Gemini South's newly operational Gemini High-resolution Optical Spectrograph (GHOST) instrument, which captures specific wavelengths of light given off by different molecules, played a key role in the study. It peered deeper into the cloud than other telescopes can, enabling the researchers to probe exactly what the cloud was made of.

The results "exceeded all expectations," revealing an abundance of metals, such as iron and calcium, Zakamska said. The GHOST data also enabled the team to track subtle movements within the cloud, which is "something we've never been able to do before in a system like this," she added.

After reviewing the cloud's movements, it quickly became clear that the metallic mass was being held together by a hefty object at its center. Based on the size of the cloud, this could either be a gas giant several times larger than Jupiter, a low-mass star in a binary pair with J0705+0612, or a brown dwarf — a sort of planet-star hybrid that's more massive than Jupiter but not massive enough to sustain nuclear fusion in its core.

If the cloud surrounds a star, then it would be classified as a circumsecondary disk because its host star is the secondary, or smaller, star in its binary pair. But if it is being held together by a planet, then it would be dubbed a circumplanetary disk. The researchers suggest the cloud is more likely held together by a star, due to high levels of infrared radiation glowing from the cloud. However, it is too early to tell for sure.

The next mystery is how the cloud formed. The researchers predict that the cloud is around 2 billion years old, hinting that it is younger than J0705+0612, which is likely closer in age to the sun (around 4.6 billion years old). This would mean that it is not left over from the star system's creation, like most other similar disks.

Instead, the researchers predict that it was birthed by a planetary collision, similar to the one that birthed the moon. This would not only explain the cloud's age but also its surprisingly high metal content, the researchers argue.

"This event shows us that even in mature planetary systems, dramatic, large-scale collisions can still occur," Zakamska said. "It's a vivid reminder that the universe is far from static — it's an ongoing story of creation, destruction, and transformation."

Researchers will likely learn more about this mysterious cloud in 2068, when it will next pass between J0705+0612 and Earth.

New evidence of ancient rivers suggests Mars may have been a "blue planet," thanks to an ocean spanning its entire northern hemisphere.

Cameras from several Mars orbiters captured the dusty remnants of apparent river deltas, which were described in research published Jan. 7 in the journal NPJ Space Exploration.

The team, led by researchers at the University of Bern, peered at the famed Valles Marineris, which is the largest valley system on Mars and five times longer than the Grand Canyon. Around this Red Planet region, scientists spotted "structures near the canyon system that resemble river deltas on Earth," University of Bern representatives wrote in a statement.

"These structures represent the mouth of a river into an ocean," the statement added. "The new study thus provides clear evidence of a coastline, and consequently, of an earlier ocean on Mars."

Water, water everywhere

Although Mars is dry and dusty today, there are many signs that the planet hosted water in the ancient past. For example, Mars rovers have spotted "blueberry stones" that may include iron oxide minerals containing water. NASA's Curiosity rover imaged possible "ripples" of an ancient riverbed in 2025, and some orbital missions have spotted what may be vast underground stores of water.

The new study focused on Martian geomorphology — the study of the surface and its processes — and employed several spacecraft, including the ExoMars Trace Gas Orbiter, Mars Express and the Mars Reconnaissance Orbiter (which recently shared its 100,000th photo).

"The unique high-resolution satellite images of Mars have enabled us to study the Martian landscape in great detail by surveying and mapping," Ignatius Argadestya, lead author of the study and a doctoral student at the University of Bern Institute of Geological Sciences as well as the university’s Physics Institute, said in the statement.

"When measuring and mapping the Martian images, I was able to recognize mountains and valleys that resemble a mountainous landscape on Earth," Argadestya said. "However, I was particularly impressed by the deltas that I discovered at the edge of one of the mountains."

The team saw possible "fan deltas," which form when debris and sand pile up in still water. The deposits in the Martian imagery appear very similar to active fan deltas on Earth, according to the team; on our planet, these deltas pile up at entry points where rivers flow into the ocean.

All of the "deposits" were mapped at an elevation of between 11,975 and 12,300 feet (3,650 to 3,750 meters) and formed roughly 3.37 billion years ago. Given that all of the deposits are at roughly the same elevation and in a region in the northern lowlands of Mars and Valles Marineris, the researchers argue that these structures mark the boundaries of an ancient shoreline. It's likely the ocean that once flowed there spanned Mars' entire northern hemisphere, the team added.

In part drawing on past research, the scientists say this ancient Martian ocean was at least as large as the present-day Arctic Ocean.

"We are not the first to postulate the existence and size of the ocean," Fritz Schlunegger, a geology professor at the University of Bern and co-author of the study, said in the statement. "However, earlier claims were based on less precise data and partly on indirect arguments. Our reconstruction of the sea level, on the other hand, is based on clear evidence for such a coastline, as we were able to use high-resolution images."

Astronomers have gotten a rare glimpse at four baby planets as they're growing up, and it reveals something surprising: These toddler worlds are getting lighter as they age.

The quadruplet worlds orbit in tightly packed paths around the star V1298 Tau, a young system that's just 20 million years old (compared with our sun's 4.5 billion years) located about 350 light-years from Earth. A new analysis, which drew on a decade of observations, shows that the planets are surprisingly lightweight, with low densities — so puffed up, in fact, that researchers likened them to Styrofoam.

The findings offer a rare snapshot of planetary architecture just after formation, the researchers said — a long-sought-for "missing link" between newborn disks of gas and dust and the mature planetary systems astronomers commonly observe across the Milky Way.

Those older systems are often crowded with planets between the sizes of Earth and Neptune on tight, Mercury-like orbits. The origins of such worlds have remained one of astronomy's enduring mysteries.

"What's so exciting is that we're seeing a preview of what will become a very normal planetary system," study lead author John Livingston, an assistant professor at the National Astronomical Observatory of Japan, said in a statement. "We've never had such a clear picture of them in their formative years."

Over time, the bloated worlds around V1298 Tau are expected to shrink as they shed their thick atmospheres, eventually becoming super-Earths and sub-Neptunes — planetary types that are absent from our own solar system but ubiquitous throughout the galaxy.

By capturing the planets at such a pivotal stage of development, the study, published Jan. 7 in the journal Nature, enables astronomers to trace the chaotic processes that sculpt planetary systems over billions of years.

'I couldn't believe it!'

The four planets orbiting V1298 Tau were first identified in 2019 in data from NASA's Kepler space telescope. One is roughly Jupiter-size, while the other three fall between the sizes of Neptune and Saturn.

What immediately set the system apart was its crowded layout of multiple oversized planets packed into relatively tight orbits — a configuration known in only one other system, Kepler-51, among more than 500 known multi-planet systems.

While the planets' existence was clear, their fundamental properties remained elusive. To pin them down, Livingston and his team embarked on a nearly decade-long observation campaign using half a dozen telescopes in space and on the ground. They tracked the planets as they passed in front of their star — events known as transits, which cause tiny dips in starlight that reveal a planet's size and orbital period.

Crucially, small variations in the timing of the transits, caused by the planets tugging gravitationally on one another, enabled the team to measure their masses. The technique is especially powerful because it is largely immune to interference from stellar flares common around young stars, the study noted.

But the method only works if astronomers know each planet's orbital period precisely — and for the outermost planet, V1298 Tau e, that information was missing. Only two of its transits had ever been observed, separated by 6.5 years across observations from Kepler and NASA's exoplanet-hunting Transiting Exoplanet Survey Satellite (TESS) telescope, leaving astronomers unsure how many transits had gone unseen in between, according to the study.

A stroke of good luck came when the ground-based Las Cumbres Observatory network — which operates telescopes in the United States, Chile and South Africa — spotted a third transit, enabling the researchers to finally lock down the planet's orbit and model the system's full gravitational choreography.

"I couldn't believe it!" study co-author Erik Petigura, an assistant professor of astronomy and astrophysics at UCLA, said in the statement. "The timing was so uncertain that I thought we would have to try half a dozen times at least. It was like getting a hole-in-one in golf."

The results showed that despite being five to 10 times Earth's radius, the planets have masses only five to 15 times greater than Earth's, making them among the least dense planets ever discovered, Livingston said.

"By weighing these planets for the first time, we have provided the first observational proof," study co-author Trevor David, an astrophysicist formerly at the Flatiron Institute in New York, who led the system's discovery in 2019, said in the statement. "They are indeed exceptionally 'puffy,' which gives us a crucial, long-awaited benchmark for theories of planet evolution."

The team then simulated the planets' evolution and found that they have already lost much of their original atmospheres and cooled faster than predicted by standard models.

"But they're still evolving," study co-author James Owen, an associate professor of astrophysics at Imperial College London, said in the statement. The planets are expected to continue shedding gas and contracting into super-Earths and sub-Neptunes, he said.

"Over the next few billion years, they will continue to lose their atmosphere and shrink significantly, transforming into the compact systems of super-Earths and sub-Neptunes we see throughout the galaxy," Owen added.

If you've seen illustrations or models of the solar system, maybe you noticed that all the planets orbit the Sun in more or less the same plane, traveling in the same direction.

But what is above and below that plane? And why are the planets' orbits aligned like this, in a flat pancake, rather than each one traveling in a completely different plane?

I'm a planetary scientist who works with robotic spacecraft, such as rovers and orbiters. When my colleagues and I send them out to explore our solar system, it's important for us to understand the 3D map of our space neighborhood.

Which way is 'down'?

Earth's gravity has a lot to do with what people think is up and what is down. Things fall down toward the ground, but that direction depends on where you are.

Imagine you're standing somewhere in North America and point downward. If you extend a line from your fingertip all the way through the Earth, that line would point in the direction of "up" to someone on a boat in the southern Indian Ocean.

In the bigger picture, "down" could be defined as being below the plane of the solar system, which is known as the ecliptic. By convention, we say that above the plane is where the planets are seen to orbit counterclockwise around the Sun, and from below they are seen to orbit clockwise.

Even more flavors of 'down'

Is there anything special about the direction of down relative to the ecliptic? To answer that, we need to zoom out even farther. Our solar system is centered on the Sun, which is just one of about 100 billion stars in our galaxy, the Milky Way.

Each of these stars, and their associated planets, are all orbiting around the center of the Milky Way, just like the planets orbit their stars, but on a much longer time scale. And just as the planets in our solar system are not in random orbits, stars in the Milky Way orbit the center of the galaxy close to a plane, which is called the galactic plane.

This plane is not oriented the same way as our solar system's ecliptic. In fact, the angle between the two planes is about 60 degrees.

Going another step back, the Milky Way is part of a cluster of galaxies known the the Local Group, and — you can see where this is going — these galaxies mostly fall within another plane, called the supergalactic plane. The supergalactic plane is almost perpendicular to the galactic plane, with an angle between the two planes of about 84.5 degrees.

How these bodies end up traveling paths that are close to the same plane has to do with how they formed in the first place.

Collapse of the solar nebula

The material that would ultimately compose the Sun and the planets of the solar system started out as a diffuse and very extensive cloud of gas and dust called the solar nebula. Every particle within the solar nebula had a tiny amount of mass. Because any mass exerts gravitational force, these particles were attracted to each other, though only very weakly.

The particles in the solar nebula started out moving very slowly. But over a long time, the mutual attraction these particles felt thanks to gravity caused the cloud to start to draw inward on itself, shrinking.

There would have also been some very slight overall rotation to the solar nebula, maybe thanks to the gravitational tug of a passing star. As the cloud collapsed, this rotation would have increased in speed, just like a spinning figure skater spins faster and faster as they draw their arms in toward their body.

As the cloud continued shrinking, the individual particles grew closer to each other and had more and more interactions affecting their motion, both because of gravity and collisions between them. These interactions caused individual particles in orbits that were tilted far from the direction of the overall rotation of the cloud to reorient their orbits.

For example, if a particle coming down through the orbital plane slammed into a particle coming up through that plane, the interaction would tend to cancel out that vertical motion and reorient their orbits into the plane.

Eventually, what was once an amorphous cloud of particles collapsed into a disc shape. Then particles in similar orbits started clumping together, eventually forming the Sun and all the planets that orbit it today.

On much bigger scales, similar sorts of interactions are probably what ended up confining most of the stars that make up the Milky Way into the galactic plane, and most of the galaxies that make up the Local Group into the supergalactic plane.

The orientations of the ecliptic, galactic and supergalactic planes all go back to the initial random rotation direction of the clouds they formed from.

So what's below the Earth?

So there's not really anything special about the direction we define as "down" relative to the Earth, other than the fact that there's not much orbiting the Sun in that direction.

If you go far enough in that direction, you'll eventually find other stars with their own planetary systems orbiting in completely different orientations. And if you go even farther, you might encounter other galaxies with their own planes of rotation.

This question highlights one of my favorite aspects of astronomy: It puts everything in perspective. If you asked a hundred people on your street, "Which way is down?" every one of them would point in the same direction. But imagine you asked that question of people all over the Earth, or of intelligent life forms in other planetary systems or even other galaxies. They'd all point in different directions.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

NASA's Mars Sample Return program has been effectively cancelled, meaning the best evidence of life on Mars could be trapped in rock samples that NASA no longer has the budget to collect.

On Monday (Jan. 15), the U.S. Senate approved a spending bill that reverses the Trump administration’s decision to halve federal spending on science and slash NASA's budget by nearly a quarter.

Yet the bill contains an exception: The Mars Sample return program, supposed to return rock samples collected by the Perseverance rover that may contain ancient signs of life, is still cancelled.

"The agreement does not support the existing Mars Sample Return (MSR) program," lawmakers wrote in an accompanying report published on Jan. 6.

There's no guarantee that life ever existed on Mars, but if it did, then the Perseverance rover may already have the evidence. This makes the new bill a major blow to those hoping to examine Perseverance's haul of more than 30 geological samples, which includes a sample NASA described as "the clearest sign of life" ever found on Mars.

But bringing samples from Mars back to Earth was always going to be a costly endeavour, and the MRS program has been fraught with delays and spiraling costs. In January 2025, an independent review board calculated that the price tag could swell to $11 billion, with samples not expected back on Earth until 2040.

In a major overhaul of the program, NASA announced that it would pursue two different strategies for fetching the samples: a tried and tested landing system that deployed a rocket-powered sky crane at a total estimated cost of between $6.6 billion and $7.7 billion, and a commercial option whose price would fall somewhere between $5.8 billion and $7.1 billion. NASA planned to announce a decision between these options in the latter half of 2026.

Yet while the Senate’s move ostensibly supports the White House's bid to kill the program, the funding bill could leave NASA space to revive the MSR. The bill, which recognizes that technologies developed as part of the MSR program were critical to the success of future space missions and human exploration of the moon and Mars, allocates $110 million to the Mars Future Missions program, including existing MSR efforts for "radar, spectroscopy, entry, descent, and landing systems, and translational precursor technologies."

In other words, there's funding for some of the tech that the program was working to develop, while falling far short of the total estimated mission costs. The allocation of $110 million nevertheless gives hope for the future of sample return, according to The Planetary Society, which campaigned against more severe proposed cuts to NASA's science program.

The new bill pledges $24.4 billion to NASA, with $7.25 billion of that assigned to the space agency's Science Mission Directorate. That means Congress only cut the NASA science portion of the budget by 1% compared to last year — a significantly more modest reduction than the 47% cut proposed by the Trump administration.

Lawmakers also committed funds to other NASA science projects in the bill. The agreement allocates $500 million for the Dragonfly mission to Saturn's moon Titan, $208 million for the active James Webb Space Telescope and $300 million for the recently completed Nancy Grace Roman Space Telescope, which is set to hunt for alien worlds and search for the true nature of dark matter when it launches as early as this fall.

The funding bill now awaits President Trump’s signature to become law.

If the U.S. does abandon the dream of returning samples from Mars, it will leave China without competition. China's Tianwen-3 sample return mission aims to collect fewer samples in a more accessible and less promising site than where Perseverance has looked for potential signs of life. However, the Tianwen-3 mission is scheduled to launch in 2028 and return rocks in 2031. If sample return is a race, then China could be set to win it.

"It is difficult to understand how the cancellation of MSR is anything but an admission that returning samples from Mars is too hard for the United States," Victoria Hamilton, leading space scientist at the Southwest Research Institute and chair of the Mars Exploration Program Analysis Group (MEPAG), told Live Science's sister-site Space.com on Jan. 12. "How do we expect to be successful at something orders of magnitude more ambitious and costly as the Moon to Mars program, where human lives are at stake?"

This weekend brings a prime opportunity to see the biggest planet in the solar system shining at its brightest all year.

After dominating the night sky for more than a month, Jupiter will reach opposition this Saturday (Jan. 10). This marks the point when Earth lies directly between Jupiter and the sun, putting the gas giant opposite our star in Earth's sky. The result is a brilliant, unmissable light in the eastern evening sky that shines all night long. At magnitude -2.7, Jupiter will outshine every star for many weeks.

(In astronomy, a lower magnitude corresponds to a brighter object. Sirius, the brightest star in the night sky, has an apparent magnitude of about -1.4.)

Shining in the constellation Gemini near the bright stars Pollux and Castor, Jupiter's opposition is the best time to see the giant planet because it rises at sunset, climbs highest around midnight, and sets at dawn. It's a prime opportunity for both novice and experienced skywatchers to get an extraordinary look at the "king of the planets."

How to see Jupiter and its moons

To marvel at Jupiter's dominance at night, you'll need nothing more than a clear sky. However, even a modest pair of binoculars (8×42 or 10×50) will reveal Jupiter as more than just a bright dot; you'll see a small, steady disk and the planet's four largest moons: Io, Europa, Ganymede and Callisto. Known as the Galilean moons, they appear as tiny points of light lined up beside the planet, changing position each night.

With a small telescope, the view becomes even more impressive. Use a low-power eyepiece to center Jupiter in your field of view, and then switch to a higher magnification. Two or more dark cloud bands should be visible crossing the planet's disk — signs of Jupiter's powerful jet streams. Under steady atmospheric conditions, the famous Great Red Spot — a massive storm that's been raging on Jupiter for around 190 years — also may come into view in the planet's southern hemisphere.

While Jupiter steals the show, Saturn is also visible in the early evening sky, hanging lower in the southwest after sunset. Though fainter, its iconic rings are still visible through a telescope — a treat for any observer.

Jupiter will remain well placed for evening viewing throughout January and into February. It's an ideal time to observe it under dark skies, before it gradually shifts westward in the coming months.

Jupiter won't disappear after opposition. On June 9, it will form a striking triple conjunction with Venus and Mercury in the twilight sky. Then, on Nov. 15, it meets Mars in a spectacular close conjunction just before sunrise.

The next opposition of Jupiter will occur on Feb. 6, 2027.

The interiors of Uranus and Neptune may be rockier than scientists previously thought, a new computational model suggests — challenging the idea that the planets should be called "ice giants."

The new study, published Dec. 10 in the journal Astronomy & Astrophysics, may also help to explain the planets' puzzling magnetic fields.

Uranus and Neptune are relatively large planets at the edge of the solar system; Neptune is the most distant planet, orbiting at 2.8 billion miles (4.5 billion kilometers) from the sun, on average. The extremely cold temperatures at these distances cause gases such as hydrogen, helium and water to condense into compressed ice slurries that form the planets' cores. As such, these planets have become known as ice giants.

"The ice giant classification is oversimplified as Uranus and Neptune are still poorly understood," lead study author Luca Morf, a doctoral student at the University of Zurich, said in a statement.

Far out planets

Morf and his supervisor, Ravit Helled, developed a new hybrid model in an attempt to better understand the interior of these cold planets. Models based on physics alone rely heavily on assumptions made by the modeler, while observational models can be too simplistic, Morf explained. "We combined both approaches to get interior models that are both unbiased and physically consistent," he said.

The pair started by considering how the density of each planet's core could vary with distance from the center of the planets and then adjusted the model to account for the planets' gravities. From this, they inferred the temperature and composition of the core and generated a new density profile. The team inputted the new density parameters back into the model and iterated this process until the model core fully matched current observational data.

This method generated eight total possible cores for both Uranus and Neptune, three of which had high rock-to-water ratios. This shows that the interiors of Uranus and Neptune are not limited to ice, as previously thought, the researchers said.

All of the modeled cores had convective regions where pure water exists in its ionic phase. This is where extreme temperatures and pressures cause water molecules to break apart into charged protons (H⁺) and hydroxide ions (OH^-). The team thinks such layers may be the source of the planets' multiple magnetic fields, which cause Uranus and Neptune to have more than two poles. The model also suggests that Uranus' magnetic field is generated closer to its center than Neptune's is.

"One of the main issues is that physicists still barely understand how materials behave under the exotic conditions of [high] pressure and temperature found at the heart of a planet [and] this could impact our results," Morf said. The team aims to improve their model by including other molecules, like methane and ammonia, which also may be found in the cores.

"Both Uranus and Neptune could be rock giants or ice giants depending on the model assumptions," Helled said. She noted that much of our understanding of these planets may be incomplete, as it's based largely on data collected by the Voyager 2 space probe in the 1980s.

"Current data is insufficient to distinguish the two, and we therefore need dedicated missions to Uranus and Neptune that can reveal their true nature," Helled added

The team hopes the model may act as an unbiased tool for any new data from future space missions to these planets.

A few months from now, a NASA spacecraft called the Mars Reconnaissance Orbiter (MRO) will begin its 20th year of observing the Red Planet from above. And, like most 20-year-olds on Earth, MRO's camera roll is absolutely packed.

According to NASA, MRO has just taken its 100,000th photo of the Martian surface using its HiRISE camera. Put another way, that's an average of 5,000 photos a year, 417 photos a month, or about 14 a day every day since March 2006.

The new milestone image, snapped on Oct. 7, shows a shadowy wasteland of mesas, craters and dunes known as Syrtis Major. This region is just southeast of Jezero Crater, the ancient lakebed where NASA's Perseverance rover is hunting for evidence of life, and appears as an enormous dark spot when seen from afar by space telescopes like Hubble.

MRO has observed the region many times before, and has previously turned up evidence that the sand dunes there are slowly migrating across the planet's surface.

"HiRISE hasn't just discovered how different the Martian surface is from Earth, it's also shown us how that surface changes over time," Leslie Tamppari MRO's deputy project scientist at NASA's Jet Propulsion Laboratory, said in a statement. "We've seen dune fields marching along with the wind and avalanches careening down steep slopes."

Studying how the Red Planet changes over time will help demystify the forces that govern it, and help reveal whether it was ever a lush waterworld like Earth. Launched from Florida on Aug. 12, 2005, and inserted into Mars orbit on March 10, 2006, the MRO will continue its mission to photograph the planet as long as it's able.

Occasionally, MRO does take a break from its primary mission to gaze off into space. In October, the satellite looked skyward to snap a shot of the interstellar comet 3I/ATLAS as it passed about 19 million miles (30 million kilometers) from the spacecraft — significantly closer that the comet got to Earth at its closest point on Dec. 19.

While MRO wasn't designed to observe small, fast-moving objects at such great distances, it nevertheless provided early confirmation that 3I/ATLAS showed the telltale characteristics of a natural comet, including a small nucleus enshrouded in a bright coma of gas and dust.

If you peer at the sky during a cloudless dawn or dusk, you'd immediately spot Venus. Appearing as a brilliant, steadily shining speck, it's the second-brightest object in the night sky after the moon.

"The planet is about 100 times brighter than a first magnitude star," Anthony Mallama, a researcher at the IAU's Centre for Protection of the Dark and Quiet Sky, told Live Science in an email. First magnitude stars are the brightest stars visible in the night sky. For example, when looking at average brightness, the first magnitude star Sirius is at -1.47, and Venus is at -4.14 (on the scale astronomers use, dimmer objects have a more positive magnitude).

But what makes Venus super-bright? Astronomical research suggests several factors can change how luminous Venus appears from Earth.

Reflective cloud cover

Venus' shininess is largely due to the planet's high albedo, or the amount of light reflected off its surface. Venus has an albedo of 0.76, meaning it scatters about 76% of the sunlight it receives back into space, according to Sanjay Limaye, a distinguished scientist in the Space Science and Engineering Center at the University of Wisconsin-Madison. In contrast, a perfect mirror would bounce off 100%, Earth bounces 30% and the moon has a low albedo, reflecting just 7% of the light that hits it.

Venus' high albedo arises from a thick, all-swaddling cloak of clouds. Extending from 30 miles to 43.5 miles (48 to 70 kilometers) above the Venusian surface, these decks of clouds are cushioned between haze layers, and are mostly suspended droplets of sulfuric acid, according to a 2018 review of data from 1970s and 1980s space missions to Venus. Limaye noted that such droplets are tiny, mostly about the size of a bacterium. Together, the droplets and haze layers scatter sunlight extremely efficiently.

But Venus isn't the solar system's shiniest object. Saturn's ice-covered moon Enceladus has a high albedo of around 0.8, a 2010 study noted. From Earth, though, this cosmic object appears much dimmer than Venus. That's because it's much farther from the sun. While Earth's "morning star" is 67 million miles (108 million km) from the sun, Enceladus is at least 13 times as distant. The inverse square law shows that Venus consequently receives 176 times more intense light compared to Enceladus, giving it a significant edge.

Distance from Earth

Being close to Earth also influences Venus' brightness. The average Venus-Earth distance is 105.6 million miles (170 million km). Sometimes, Mercury is the closest planet to Earth at an average distance of 96.6 million miles (155.5 million km), but Venus' larger size (of 7,521 miles (12,104 km) compared to Mercury causes it to look brighter.

But Venus' distance from our planet — and consequently, its apparent luminosity — aren't fixed. At its closest, when Venus lies directly between Earth and the sun, it's a mere 24 million miles (about 38 million km) away, according to NASA. Yet at this point — called the inferior conjunction — it's actually extremely dim, according to the National Astronomical Observatory of Japan.

This arises because the inner planets show moon-like phases when viewed from Earth, Limaye said. At inferior conjunction, Venus' illuminated surface is completely invisible from Earth. In contrast, most of Venus' illuminated surface can be seen only when Earth and Venus are on opposite sides of the sun, a position called the superior conjunction. At this point, though, Venus is at its smallest and is very dim because it is extremely far from Earth.

A rainbow-like phenomenon

Venus is at its brightest when only a crescent-like sliver of its sunlit surface can be seen. Termed the point of greatest brilliancy, this typically occurs a month before and after the inferior conjunction. A 2006 study co-authored by Mallama suggested that, at this phase, Venus' suspended sulfuric acid droplets scatter sunlight toward Earth. "This phenomenon is called a glory and it is in the same family of optical effects that includes rainbows," Mallama explained.

Together, variations in the albedo, its distance from the Earth and sun, and its phases seen from Earth can all cause the brightness of Venus to swing from -4.92 to -2.98, according to a 2018 study. However this is still luminous enough to make Venus viewable most of the year, even from urban areas.

Solar system quiz: How well do you know our cosmic neighborhood?

Astronomers hoping to observe a planet around a nearby star have witnessed a much rarer "unprecedented celestial event," the team said: The violent aftermath of not one, but two collisions between the rocky building blocks of planets.

Over the past two decades, astronomers witnessed two separate catastrophic collisions around the star Fomalhaut, located just 25 light-years away in the constellation Piscis Austrinus. The detections occurred after planetesimals (rocky pieces of unformed planets) measuring much larger than the dinosaur-killing asteroid smashed each other into massive clouds of glittering debris.

The Fomalhaut system is no stranger to such crashes. It's famously known as the "Eye of Sauron" due to its resemblance to the fiery, all-seeing eye from J.R.R. Tolkien's Lord of The Rings franchise. The likeness comes from the spectacular dust belt that surrounds Fomalhaut at a distance of 133 astronomical units (AU), with one AU being equal to 93 million miles (150 million km) — the average distance between the sun and Earth.

Formed from countless rocky, icy collisions, this belt of dust and debris provides a dustier analog of our early solar system as it appeared more than 4 billion years ago, the team said — offering a glimpse of our neighborhood's chaotic infancy, when planets were being created, destroyed, and reassembled.

False planet syndrome

A new study, conducted by an international team of researchers and led by Paul Kalas, an astronomer at the University of California, Berkeley, described these two collision events in destructive detail to help solve a planetary mystery.

In the early 2000s, astronomers observing the Fomalhaut system spotted a large, luminous object that many assumed to be a dust-covered exoplanet reflecting light. They designated this exoplanet candidate Fomalhaut b.

Yet when this supposed planet blinked out of existence and another bright point of light appeared nearby, all in the span of approximately 20 years, researchers realized they weren't viewing planets, but the shining debris clouds formed by what they call a "cosmic fender bender."

Fomalhaut forensics: a history of catastrophic crashes

The two collision events, now known as Fomalhaut cs1 and Fomalhaut cs2, appear to be incredibly serendipitous. Theory suggests that collisions of this size should only happen once every 100,000 years or so, but the Fomalhaut system surprised scientists with two such smash-ups in just 20 years.

Indeed, based on this timeline, the study infers that 22 million similar events may have occurred during the Fomalhaut system's relatively young, 440-million-year-old life so far. Even if one could rewind only the past 3,000 years or so, "Fomalhaut's planetary system would be sparkling with these collisions," Kalas explained in a statement.

Reverse engineering the collisions based on factors like the mass of the debris clouds and the size of the dust grains suggests that Fomalhaut cs1 and cs2 were the result of colliding planetesimals around 37 miles (60 km) in diameter, or around four to six times the size of the asteroid that devastated the non-avian dinosaurs 66 million years ago.

It's an alien event with a relatable twist: "These larger bodies are like the larger bodies that comprise our own asteroid and Kuiper belts," study co-author Jason Wang, an astronomer at Northwestern University, told Live Science via email.

And there are a lot of these bodies. Based on their reconstruction of the event, the researchers suggest that the Fomalhaut system may host 1.8 Earth masses of these primordial planetesimals. This may amount to about 300 million such bodies, according to a separate statement.

Furthermore, the system holds another 1.8 Earth masses in smaller bodies measuring less than 0.186 miles (0.3 kilometers) across. These relative runts constantly replenish the tiny dust grains, many just a few 10,000ths of an inch in size, that swirl and shimmer in Fomalhaut's dust belt. Without this rocky reservoir, the dust belt would disappear as its grains are blown out of the system by stellar wind or engulfed by its star.

The planet that never was, still may be

Even though Fomalhaut b no longer exists — as a planet, at least — this "planet that never was" may actually still be hiding within the system.

Researchers calculated that, given the specific conditions, there's about a 10% chance that Fomalhaut cs1 and cs2 are not random collisions. Their similar timing and location may point to a hidden influence, such as the ghostly gravitational pull of an unseen exoplanet.

"For example, something — like planets — should be responsible for carving out the planetesimals into a dust belt that we see," Wang told LiveScience. "Additionally, we speculate that the proximity in location of the cs1 and cs2 impact sites may be driven by a planet that preferentially causes planetesimals to collide there."

Playing planetary peek-a-boo

This exoplanetary confusion highlights an important consideration for planet-hunters, and for next-generation facilities like NASA's Habitable Worlds Observatory that are designed to directly image habitable-zone exoplanets in the nearby universe: "Fomalhaut cs2 looks exactly like an extrasolar planet reflecting starlight," explained Kalas.

As a result, this unique study not only informs our ideas about planetary formation, such as collision rates and debris belt mechanics, but can also help astronomers more precisely identify planetary bodies from among all the other shining celestial objects with which the universe continually dazzles us.

A mysterious, spider-like structure lurking on Jupiter's fourth-largest moon, Europa, may finally have a proper explanation nearly 30 years after it was discovered. The arachnid imposter has also been given a demonic new name.

In March 1998, NASA's Galileo spacecraft — which studied Jupiter and its major moons between 1995 and 2003 — made a close flyby of Europa, a frozen ocean moon often considered one of the most likely places for extraterrestrial life to exist in the solar system. During this flyby, the probe mapped out a roughly 13.7-mile-wide (22 kilometers) impact structure, dubbed Manannán Crater, on the moon's icy surface, and found something strange lurking within it.

Hidden inside a deep pit near the crater's center was a sprawling dendritic shape. The researchers initially believed the dark feature was caused by the extreme gravitational force exerted on Europa by Jupiter, which is responsible for carving multiple fracture lines across the water world's surface. Other experts have since proposed that it was created by eruptions from hydrothermal vents on the floor of Europa's subsurface ocean. However, neither of these explanations fully explain this unusual shape.

But in a new study, published Dec. 2 in The Planetary Science Journal, researchers proposed an alternative explanation: that the Jovian spider formed in a similar way to how dark dendritic patterns on Earth, known as "lake stars," typically do. These features form when snow falls on frozen lakes and water seeps up through tiny holes in the ice.

With this in mind, the researchers used a similar technique to partially recreate the Manannán Crater's mysterious shape in the lab. The study team also finally named Europa's arachnid-like asterisk Damhán Alla, meaning "spider" or "wall demon" in Irish. (Manannán is a Celtic god from Irish mythology, which partly inspired the new name.)

"Lake stars are really beautiful, and they are pretty common on snow or slush-covered frozen lakes and ponds," study lead-author Lauren Mc Keown, a planetary scientist at the University of Central Florida, said in a statement. "It is wonderful to think that they may give us a glimpse into processes occurring on Europa and maybe even other icy ocean worlds in our solar system."

However, rather than water rising through tiny holes, as happens when lake stars form on Earth, Damhán Alla was likely birthed by an asteroid impact — which created a small crack in Europa's icy shell that enabled salty water to seep upward and paint the spider-like pattern on the surface. (This asteroid impact likely happened after the Manannán Crater was already formed.)

The researchers also noted similarities between Damhán Alla and the infamous "spiders on Mars," which are dusty deposits on the Martian surface that look like swarming spiders when viewed from above. These fake arachnids, known as araneiform terrain, form when submerged carbon dioxide ice sublimates, or turns directly into a gas. Mc Keown's team has previously recreated these features on Earth too.

The similarities in shape between Damhán Alla and the spiders on Mars are due to how "fluid flows through porous surfaces," Mc Keown said. In theory, similar spider features could also form on other frozen ocean worlds, such as Saturn's moon Enceladus, Jupiter's other moon Ganymede and the dwarf planet Ceres, which resides in the asteroid belt beyond Mars.

Mc Keown is now setting up a new laboratory, which will focus on studying how these various spider-like features may form on different solar system moons. She hopes to be able to provide valuable insight that could help inform NASA's Europa Clipper mission, which launched in October 2024 and will arrive to extensively study Jupiter's watery moon in 2030.

"The significance of our research is really exciting," Mc Keown said. "Surface features like these can tell us a lot about what's happening beneath the ice. If we see more of them with Europa Clipper, they could point to local brine pools below the surface," she added.

And these pools could be a good place to start looking for signs of extraterrestrial life.

Saturn's largest moon, Titan, may be hiding a habitable world of slushy sea ice, new research hints.

Back in 2008, NASA's Cassini spacecraft gathered data on Titan that suggested an open ocean might lurk beneath the moon's frozen crust. But the new analysis hints that what lies underneath is instead "slushy tunnels and pockets of meltwater," according to the investigators.

The results, published Wednesday (Dec. 17) in the journal Nature, have large implications for our understanding of how common water is on other worlds. If confirmed, the work may also influence our search for life on other worlds, as water is a key ingredient for life.

"Instead of an open ocean like we have here on Earth, we're probably looking at something more like Arctic sea ice or aquifers, which has implications for what type of life we might find, [and] also the availability of nutrients, energy and so on," study co-author Baptiste Journaux, an assistant professor of Earth and space sciences at the University of Washington, said in a statement.

The "smushing" moon

The story begins with Cassini, a spacecraft that launched in 1997 and spent much of its 20 years observing Saturn and its moons. Cassini spotted the shape of Titan "stretching and smushing" as it circled Saturn, according to the authors of the new study. Back then, the researchers proposed that if Titan possessed a deep ocean, that would let the crust flex under the pull of Saturn's gravity.

Now, the new study takes into account the timing of Titan's flexes. The team found that the shape of Titan begins to change only about 15 hours after Saturn exerts its strongest gravitational pull in Titan's orbit. The scientists then estimated the energy it would take for Titan's shape to alter, which, in turn, showed more about the mysterious moon's interior.

"Nobody was expecting very strong energy dissipation inside Titan," lead study author Flavio Petricca, a postdoctoral fellow at NASA's Jet Propulsion Laboratory, said in the statement. "That was the smoking gun indicating that Titan's interior is different from what was inferred from previous analyses."

Historically, Titan has always been hard to observe. The planet is shrouded in a thick, orange atmosphere that's rich in chemical compounds that may be precursors to life. Looking at the surface requires radar (which Cassini possessed, whereas predecessor flyby missions Voyager 1 and Voyager 2 did not). Cassini's observations revealed a bizarre surface where methane falls as rain, seas constantly shift, and temperatures stand around minus 297 degrees Fahrenheit (minus 183 degrees Celsius).

Titanic slushies

So what is going on in Titan’s interior? The new study says below the frozen exterior, the moon's innards appear to have ice, meltwater pockets and overall, a slushier environment than believed in 2008. The slush is thick and likely accounts for the observed lag in Titan's shape shifts. While water is believed to be in the slush, it wouldn't be as liquid as an open ocean, the team found.

Aside from recycling the old Cassini radio-wave observations, the researchers used new thermodynamic models developed by Journaux's lab to study how water, minerals and other components behave on worlds like Titan.

"The watery layer on Titan is so thick, the pressure is so immense, that the physics of water changes," Journaux said. "Water and ice behave in a different way than sea water here on Earth."

Expanding the search for life

While at first this lack of a full ocean sounds like a blow to the search for life, the research team emphasized that instead, "It expands the range of environments we might consider habitable," Jones said.

Scientists also found that “pockets of fresh water” may exist within Titan at life-friendly temperatures of 68 degrees Fahrenheit (20 degrees Celsius). Moreover, nutrients would be concentrated in small pools of this water, perhaps allowing for more rich conditions for life than a less-concentrated ocean would.

Upcoming observations may aid our understanding of Titan. NASA's Dragonfly mission is set to launch as soon as 2028, and it should arrive at Titan in 2034. It will be the second flying vehicle on another world besides Earth, after Ingenuity, a helicopter on Mars. It is hoped that Dragonfly's surface observations of Titan will reveal more about where life may be lurking and how much water might be available for organisms.

A giant, city-size "butterfly" that was carved into the surface of Mars millions of years ago just got a new photo op thanks to European Space Agency (ESA) scientists. The beautiful Martian bug, which sports a pair of smooth rocky wings, is a stunning reminder of the Red Planet's violent and watery past, experts say.

The so-called butterfly is an asymmetrical impact crater, created when a hefty asteroid smashed into Mars in the distant past at an unusually low angle. It is located in the Idaeus Fossae region — an extremely uneven and previously volcanic region in Mars' northern lowlands — and is around 12.4 miles (20 kilometers) from east to west and 9.3 miles (15 km) from north to south. This makes the crater almost large enough to fit the island of Manhattan across its floor.

The latest images of the oval crater, which remains unnamed, were digitally created using topographical data collected by ESA's Mars Express orbiter, which has been scanning the Red Planet since 2003. The data was also used to create a short video that calls the crater a "cosmic butterfly" and shows what it would look like if you were to circle it in a helicopter (see below).

Unlike most other impact craters in the solar system, which are circular and eject material equally around their edges, the shallow angle of this incoming asteroid caused it to unevenly distribute the debris, creating the crater's wings.

"The collision caused two distinct lobes of material to be flung outwards to the crater's north and south, creating two outstretched 'wings' of raised ground," ESA representatives wrote in a statement describing the butterfly. This uneven impact also sculpted the crater's floor into an "irregular," walnut-like shape, they added.

Craters like this are commonly known as butterflies because of their rounded shape and rocky wings, and they are exceedingly rare. However, this is not the first one to be spotted on Mars.

In 2006, around three years into the Mars Express orbiter's mission, the ESA spacecraft snapped a butterfly crater in the Hesperia Planum region in Mars' southern highlands. This crater is much more elongated than the Idaeus Fossae crater and arguably has a much more bug-like appearance. (Mars' southern highlands and northern lowlands lie on either side of a geographical anomaly that "splits" the planet near the equator.)

Studying these anomalous craters helps scientists better understand the angle and force of the impacts that formed them. It can also reveal clues about the hidden layers of Mars' surface and what conditions existed when the collisions occurred, according to Live Science's sister site Space.com.

In the latest case, the ESA team noticed that the wings of the butterfly are much smoother than its bobbly, walnut-like floor. This suggests that this material has been "fluidized," meaning that it has been mixed with water. This most likely happened when Martian ice buried beneath the crater was melted by the impact and released into the resulting explosion, ESA representatives wrote.

It is currently unclear exactly when the newly imaged insect crater was formed or how large and fast the meteor that birthed it was. However, fragments of the space rock could potentially remain within the crater.

Animals on Mars

This is not the first time that scientists have found animal impostors lurking on Mars' surface.

NASA's various Mars rovers have found multiple rocks that bear a striking similarity to living creatures, including a turtle poking its head out from its shell, which was snapped by Perseverance in August, and a coral-like structure photographed by the Curiosity rover in 2022.

From above, certain geological features also take on a surprising likeness to wildlife, such as the infamous "spiders on Mars," which are cracks that form when ice sublimates beneath the Martian surface and look like swarming arachnids.

In September 2024, the Mars Express orbiter also helped to reveal a hidden dog-shaped blob lurking beneath Mars' North Pole.

These animal associations are often made due to pareidolia — a psychological phenomenon in which the human mind perceives a familiar pattern, such as a face or image, in random objects or structures.

The James Webb Space Telescope (JWST) has spotted a distant exoplanet that should be impossible. The ultrahot super-Earth, named TOI-561 b, is surrounded by a thick atmosphere of hot gas that blankets a planet covered by a broiling magma ocean.

Astronomers have been surprised by several of the hell planet's features, which don't match what we've found elsewhere in the universe. The discovery could reshape what we know about the types of planets that can form and evolve.

"What's really exciting is that this new data set is opening up even more questions than it's answering," study lead author Johanna Teske, staff scientist at Carnegie Science Earth and Planets Laboratory in Washington D.C. said in a statement from NASA.

Hot, close to the sun, and tidally locked

TOI-561 b is located around 280 light-years from Earth in the constellation Sextans, and it has a radius about 1.4 times that of our own planet. It circles its sun, which is slightly smaller and cooler than our own, every 11 hours, according to the statement. That puts it in a rare class of objects known as ultra-short period exoplanets, according to NASA.

The planet orbits incredibly closely to its parent star — just 1/40th the distance between Mercury and the sun, the statement noted. That means it is "tidally locked," or keeps one side of the planet perpetually facing the star — much like Earth's moon is tidally locked with our planet. Such tidally locked planets have a permanent dayside and permanent nightside.

Too light, too cool, too atmospheric

The distant hell planet is puzzling to researchers in many ways.

For one, it has an unusually low density. That is likely because it formed very differently than the planets we are most familiar with.

"TOI-561 b is distinct among ultra-short period planets in that it orbits a very old (twice as old as the Sun), iron-poor star in a region of the Milky Way known as the thick disk," Teske said. "It must have formed in a very different chemical environment from the planets in our own solar system."

But the bigger surprise came when researchers took a look using JWST. The telescope's NIRSpec (Near-Infrared Spectrograph) instrument revealed the planet's dayside temperature by measuring how much the light from the planet dimmed as it moved behind its host star. Based on the type of star it circles and its distance, the temperature should be up to 4,900 degrees Fahrenheit (2,700 degrees Celsius) if the planet were bare rock. Yet TOI-561 b measured just 3,200 F (1,800 C).

The team tested, then discarded, a number of explanations for the anomalously cool temperature. None could explain the discrepancy except for one: that the planet has a thick atmosphere.

That defied their expectations. Planets that have been orbiting so closely to their star for so long are expected not to have an atmosphere, because eons of radiation from the parent star should have blasted it away. So how did TOI-601 b hold on to its atmosphere?

The atmosphere must contain more volatile chemicals than Earth's atmosphere does, study co-author Tim Lichtenberg, an astronomer at the University of Groningen in the Netherlands, said in the statement.

That would confer strong winds that carry heat from the planet's dayside to its permanent nightside. An atmosphere would also provide water vapor that could soak up some near-infrared light before it could pass through the atmosphere and into JWST's instruments. And bright clouds filled with silicates, a key ingredient in rocks on Earth, could also reflect starlight, study co-author Anjali Piette, an astronomer at the University of Birmingham, U.K., said in the statement.

"We really need a thick volatile-rich atmosphere to explain all the observations," Piette said.

The researchers published their findings Dec. 11 in The Astrophysical Journal Letters.

One of JWST's core missions is finding and characterizing atmospheres around exoplanets, because (as far as we know) an atmosphere is a prerequisite for life. While it's extremely unlikely that this broiling hell planet is habitable in any sense, studying its atmosphere with JWST could help scientists better understand how planetary atmospheres form, and how the powerful telescope could be best used to find evidence of alien life.

Scientists have found that time moves slightly faster on the Red Planet than it does on Earth. Clocks on Mars tick, on average, 0.477 milliseconds (477 microseconds) faster over 24 hours when measured from Earth compared with time recorded on our planet, a new study finds. Knowing this difference may help in establishing an "internet" across the solar system.

Over the next few decades, humanity's presence in the solar system is set to boom, with missions like those in NASA's Artemis program expected to pave the way for permanent settlements on the moon and beyond. Developing a standard clock for each cosmic locale would help astronauts navigate these worlds while coordinating communications with Earth.

But there's a catch: Time doesn't run at the same pace everywhere. Albert Einstein's theory of general relativity shows that time in a given area depends on how strong the gravity is there. Clocks in areas of high gravity tick more slowly than those where gravity is weaker, which is why people residing atop mountains age a fraction of a millisecond faster than sea-level dwellers. (Time appears to move faster at high altitudes, where Earth's gravitational tug is reduced.)

Additionally, time on a planet depends on its velocity around its parent star; the faster the orbital rate, the faster the passage of time.

Time keeps on slippin'

Together, velocity and gravity cause time on different solar system bodies to tick at different rates when measured from Earth. A 2024 study calculated that clocks on the moon would run an average of 56 microseconds (millionths of a second) faster than Earth-based ones. Having established this, the researchers — Neil Ashby and Bijunath Patla, both physicists at the National Institute of Standards and Technology in Boulder, Colorado — turned their attention to Mars.

First, they chose a reference level on Mars — an equivalent to Earth's sea level called the areoid. Then, they used physics-based formulas to calculate how, at the areoid, Mars' and Earth's gravities and velocities would influence Martian time. Although Mars' slower orbital speed relative to Earth slows down Mars-based clocks, the planet's weaker surface gravity — five times lesser at the areoid than Earth's sea-level gravity — speeds them up much more.

But this analysis neglected the orbits' shapes. Mars' orbit is more egg-shaped than Earth's, having been contorted by the gravitational tugs of Earth and its moon. (Mars' moons, Deimos and Phobos, have a negligible impact, Patla told Live Science in an email, because of their puny size. They're just a few miles wide, compared with 2,159 miles, or 3,475 kilometers, for Earth's moon.) So, Ashby and Patla factored Mars' orbital shape, the sun's gravity and Earth moon's gravity into their equations.

Setting clocks on Mars

The analysis showed that Martian clocks tick faster, when measured from Earth, than Earth-based ones by an average of 477 microseconds per Earth day. Strikingly, though, this value varies daily by 226 microseconds (about half the offset's value itself) over a Martian year. The variation stems from the egg-like shape of Mars’ orbit and changes in the gravitational tugs of its celestial neighbors as they approach and twirl away from Mars.

Additionally, the researchers found that the clocks change by an extra 40 microseconds over seven of Mars' synodic periods, with a synodic period being how long the planet takes to reappear in the same position of the sky.

"The fluctuation and the Earth-Mars planetary dance (synodic period) variation was a surprise," Patla said, because their magnitudes were larger than he expected.

The findings, published Dec. 1 in The Astronomical Journal, will help scientists synchronize time across the solar system, allowing them to establish rapid communications channels in an interplanetary internet in the distant future, although the large fluctuations will complicate this effort, Patla said. He added that the study "provides a baseline for future tests of general relativity and fundamental physics, which explore the nature of spacetime."

But the calculations were still inaccurate by about 100 nanoseconds (0.1 microseconds) per day over long timescales, because tiny shifts in the planets' movements weren't factored in. Although this imprecision is minuscule, it would mean resetting Martian clocks every 100 days.

The study also didn't account for factors like how the planets' orbits precess, or gradually wobble, and the effects of Earth's and Mars' gravitational quadrupole moments, which is a measure of how their mass is arranged within their structures. Taken together, these limitations may make it more challenging to obtain more precise time calculations, the researchers said.

Christians are well aware of the Nativity story, in which three wise men follow the "Star of Bethlehem" to the newborn Jesus. But does this biblical story have astronomical origins? What was the "Christmas Star"?

Modern skywatchers have posited many theories, such as the star being a very close conjunction of Venus and Jupiter in 2 B.C or a less visually striking triple conjunction of Jupiter and Saturn seen throughout 7 B.C. (Historians continue to debate the actual date of Jesus' birth.) Another theory suggests it may have been a bright stellar explosion.

There are no major close conjunctions this December, nor any naked-eye comets, exploding stars or anything else particularly unusual. However, there is a bright point of light visible for much of the night, and it's rising in the east soon after dark.

Jupiter will come to opposition on Jan. 10, 2026. On that date, Earth will be between Jupiter and the sun, putting the giant planet at its closest and brightest to Earth. When an outer planet like Jupiter is at opposition, it rises in the east at sunset, reaches its highest point in the sky around midnight, and sinks in the west at sunrise.

Whether Jupiter alone was the "Star of Bethlehem" is doubtful, because its opposition occurs every 13 months. That's because Jupiter takes 11.86 Earth years to orbit the sun once, and Earth gets between it and the sun once each year. According to Sky & Telescope, Jupiter completes about one-twelfth of its orbit each Earth year, so it takes Earth about a year to catch up to the point where it can align with Jupiter again, resulting in a 13-month opposition cycle.

In December, a month before opposition, Jupiter is rising about two hours after sunset. However, because sunset occurs early during December in the Northern Hemisphere, Jupiter dominates the sky for much of the night. Easily visible in the eastern sky after 8 p.m. local time, Jupiter dominates the night sky as a neatly timed "Christmas Star."

Shining at a very bright magnitude of -2.4 at the beginning of December, Jupiter will get even brighter as it approaches opposition, reaching -2.5 by the end of 2025. (In astronomy, a lower magnitude corresponds to a brighter object; negative magnitudes are the brightest.)

Was Jupiter the Star of Bethlehem? We may never know — but in December 2025, its brilliance will make it a worthy stand-in.

Mars was once home to wet, humid areas that received heavy rainfall, similar to tropical regions on Earth, a new study of unusually bleached rocks suggests.

Researchers were intrigued by peculiar light-colored rocks that NASA's Perseverance rover discovered on the Martian surface. Upon closer inspection, the rocks turned out to be kaolinite, an aluminum-rich type of clay, the scientists reported in the study, which was published Dec. 1 in the journal Communications Earth & Environment.

On Earth, kaolinite almost always forms under very warm, steamy conditions, such as those found in tropical rainforests. It typically forms in rocks that have been stripped of all other minerals by millions of years of regular rainfall. But present-day Mars is famously cold and dry.

"So when you see kaolinite on a place like Mars, where it's barren, cold and with certainly no liquid water at the surface, it tells us that there was once a lot more water than there is today," Adrian Broz, a soil scientist at Purdue University and lead author of the study, said in a statement.

Broz and his team compared the structure of the Martian kaolinite, which had been examined by multiple instruments on Perseverance, with terrestrial samples taken from South Africa and San Diego. The rocks appeared strikingly similar, suggesting they formed in similar ways.

Satellite images of the Martian surface appear to show larger kaolinite deposits elsewhere on the planet. However, Perseverance and other rovers have not explored those areas yet.

"Until we can actually get to these large outcroppings with the rover, these small rocks are our only on-the-ground evidence," Briony Horgan, a planetary scientist at Purdue University and co-author of the study, said in the statement.

The presence of kaolinite on Mars adds weight to the hypothesis that the Red Planet was a wet oasis at some point in the distant past, though exactly when and how it dried up are still debated.

The leading hypotheses suggest that the planet lost its water sometime between 3 billion and 4 billion years ago, when its magnetic field weakened enough for solar winds to strip away its atmosphere. But this process was likely complex and multifaceted. Studying these ancient clays could give scientists more insight into how and when Mars lost its water, the researchers said.

It could also provide clues about Mars' potential habitability, Broz said, since "all life uses water."

The catastrophic collision that forged the moon, and marked one of the most consequential events in Earth's early history, may have been triggered not by a distant interloper, but by a sibling world that grew up right next door, according to a new study.

About 4.5 billion years ago, a Mars-size world slammed into the young Earth with such tremendous force that it melted huge swaths of our planet's mantle and blasted a disk of molten debris into orbit. That wreckage eventually clumped together to form the moon we know today. Scientists have long favored this "giant impact" origin story, but where the long-lost world, nicknamed Theia, came from and what it was made of remain a mystery.

But the new analysis of moon samples from Apollo missions, terrestrial rocks and meteorites now argues that Theia, much like Earth, was a rocky world that formed in the inner solar system — likely even closer to the sun than our planet.

"Theia and proto-Earth come from a similar region of the inner solar system," Timo Hopp, a geoscientist at the Max Planck Institute for Solar System Research in Germany, who led the research, told Live Science.

The findings, detailed in a paper published Nov. 20 in the journal Science, reinforce the classical picture of how rocky planets assembled billions of years ago, Hopp said.

"Our results do not predict a new twist in the mechanism," Hopp said. Instead, they "are in very good agreement from what we expect from the classical theory of terrestrial planet formation."

Violent youth of the planets

In the turbulent first 100 million years after the sun formed, the inner solar system was crowded with dozens to hundreds of planetary embryos — moon- to Mars-size worlds that frequently collided, merged or were kicked into new orbits by the gravitational chaos of early planet formation, as well as by Jupiter's immense pull.

"Theia was one of 10-100s of planetary embryos from which our planets formed," said Hopp. But lunar samples from the Apollo missions have shown that Earth and moon are nearly chemically identical, a similarity that scientists say has made pinpointing Theia's birthplace extremely difficult.

To investigate, Hopp and his colleagues searched for minuscule chemical clues left behind from the impact in Earth's mantle — traces of elements such as iron and molybdenum that should have sunk into Earth's core if they had been present early in the planet's formation. Their survival in mantle rocks today suggests these elements arrived later, likely delivered by Theia during the giant impact, and therefore carry valuable information about the lost planet's composition, the researchers say.

Clues from the moon

The researchers analyzed six lunar samples from the Apollo 12 and 17 missions alongside 15 terrestrial rocks that included specimens from Hawaii's Kīlauea volcano, as well as meteorites recovered from Antarctica and curated in major museum collections.

The team focused on extremely subtle differences in iron isotopes (different versions of elements), which recent research shows can pinpoint where material formed relative to the sun. They combined these iron measurements with isotopic signatures of molybdenum and zirconium, then compared the results with known meteorite compositions to deduce which kinds of planetary "building blocks" could have formed Theia.

Across hundreds of modeled scenarios, from small impactors to bodies nearly half the mass of Earth, the only configuration that successfully reproduced the chemistry of Earth and the moon was the one in which Theia formed in the inner solar system, the study reports. Theia was likely a rocky, metal-cored world containing roughly 5 to 10% of Earth's mass, the team notes.

The models also reveal that both proto-Earth and Theia contain material from an "unsampled" inner-solar-system reservoir, a type of matter absent from all known meteorite collections. This mysterious component likely formed extremely close to the sun, in a region where early material was either swept up by Mercury, Venus, Earth and Theia — or never survived as free-floating bodies capable of becoming meteorites.

"It might be only sample bias," Hopp acknowledged. Samples from Venus or Mercury, he added, may someday reveal larger fractions of this missing material and could ultimately "confirm or reject our conclusion."

While the study clarifies that Earth and Theia were likely local siblings, how the giant impact mixed the two worlds so thoroughly that their chemical identities became nearly indistinguishable remains an open question, Hopp said.

Cracking that mystery may reveal the last missing chapter in the moon's violent origin story — and could be the key to fully understanding how our moon and Earth came to be.