Interstellar space just got a little sweeter: A type of sugar called erythrulose has been found near the center of the Milky Way, according to a new study.

The detection, made in a gas cloud called G+0.693-0.027, is the first time this sugar has been found outside the solar system and adds to research identifying similar life-friendly ingredients around our galaxy, such as water.

Erythrulose, which is made up of four carbon atoms, is also found in raspberries. Its interstellar presence was confirmed by the Yebes 40-meter and IRAM 30-meter radio telescopes in Spain, the research team reported Monday (July 13) in the journal Nature Astronomy. The signal of erythrulose was confirmed with patterns measured in the laboratory.

While space researchers often focus on water and carbon when searching for the ingredients of life, sugars are also essential. "Sugars are important molecules in living systems, helping to provide energy, build important biological structures, and form parts of genetic material," the researchers said in a statement.

"We were able to achieve this detection thanks to the combination of exceptionally sensitive observations, extensive frequency coverage, and highly accurate laboratory spectroscopic data," study co-author Izaskun Jiménez-Serra, a staff researcher at the Spanish National Research Council, told Live Science in an email. "In addition, our astronomical target is one of the richest chemical inventories in the galaxy, which enhances the probabilities of detection,"

Finding erythrulose, he added, "is particularly relevant for the field of origins of life" because that sugar changes the configuration of threose — yet another sugar which is believed to be the precursor of the first nucleic acids that evolved into RNA and DNA.

Sugar, space, and everything nice

Sugar has been spotted in meteorites and asteroid samples before, particularly ribose (an RNA building block) and glucose (a product of photosynthesis on Earth). Recently, for example, samples from the asteroid Bennu returned by the OSIRIS-REx mission were found to contain both ribose and glucose, suggesting that these vital ingredients for biology are available elsewhere in the solar system.

Previously, scientists could not figure out how erythrulose could be made in conditions simulating the early Earth. That's because lab experiments "yield insufficient concentrations" of erythrulose on the surface of prebiotic (pre-life) Earth, the researchers explained.

The new finding of erythrulose in an interstellar gas and dust cloud, by contrast, suggests that erythrulose could be found in the interstellar medium for incorporation into rocky planets like Earth earlier, when they are first forming and evolving.

As such, ribose, glucose and erythrulose could have been part of the "sugar inventory" on Earth before it fully formed, the researchers said. "The findings suggest that erythrulose can be made from simpler molecules on dust grains in space, and may then become part of more complex chemical systems," the team said in the statement.

The sweet detection adds further evidence to the theory that many, if not all, of the essential ingredients of life are plentiful in space.

"One of the most exciting next steps is to search for even more complex sugars and for molecules that are direct precursors of RNA, and other biologically important compounds," Jiménez-Serra told Live Science. "We want to understand how far prebiotic chemistry can progress before planets are even formed, and what chemical inventory young planetary systems inherit from interstellar space."

Two of the Milky Way's gigantic spiral arms appear to be much farther away than we realized, scientists have discovered after listening to the echoes of distant cosmic explosions. The findings could potentially force us to reconsider our galaxy's mass and maybe even its shape, researchers say.

The Milky Way is a barred spiral galaxy made up of a dense central region containing a supermassive black hole (dubbed Sagittarius A*), orbited by four major arms — the Sagitarrius arm, the Scutum-Centaurus arm, the Perseus arm and the Outer arm — that curve and stretch outward like a giant pinwheel. Most of our galaxy's stars and gas are tightly packed together in these cosmic limbs, although some stars, including the sun, exist in the gaps between them or within other smaller structures.

Until now, researchers have estimated the size of these arms based on the Milky Way's rotation rate, because it is impossible to see our galaxy's entirety from Earth's position inside the galaxy. This, in turn, has helped us estimate the galaxy's total size (around 100,000 light-years across) and its mass, which is equivalent to around 1.5 trillion suns, according to NASA.

However, this way of measuring the massive structures is not foolproof and has led to several uncertainties about our galaxy since we first discovered its spiral shape around 175 years ago, Live Science's sister site Space.com reported.

"We usually model the Milky Way's outer arms indirectly based on what we know of how our galaxy rotates, but doing it this way leaves room for error," study first author Beatrice Vaia, a researcher at the Italian National Institute for Astrophysics who led the new study as part of her doctorate, said in a statement. The farther away from the galactic center, the more uncertain the measurements become, she added.

In the new study, published June 19 in the journal Astronomy and Astrophysics, researchers came up with a new method of measuring the arms using the most powerful and luminous explosions in the universe, known as gamma-ray bursts (GRBs). As X-ray light from these cosmic outbursts passes through dense clouds of gas, like those within our galaxy's arms, it creates luminous rings, or echoes, whose size corresponds to their distance from Earth.

The team used data from NASA's Chandra X-ray Observatory and the European Space Agency's XMM-Newton observatory (both of which orbit Earth) to analyze echoes from three different GRBs that shone through gas clouds in the Perseus, Outer and Scutum-Centaurus arms, respectively. This revealed that both the Outer and Scutum-Centaurus arms are likely around 10% farther from Earth than we thought. This may not sound like much, but it equates to several thousand light-years.

The biggest potential implication of this discovery is that our galaxy is wider and, therefore, probably more massive than we realized, which could have major knock-on effects for our understanding of our cosmic neighborhood.

"The differences are small, but any revision of these distances is important because they are so fundamental for understanding our galaxy," study co-author Ilaria Fornasiero, an astronomer at the University of Bologna in Italy, said in a separate statement. "For example, this could mean that astronomers have to revise estimates of the mass of the galaxy, because that affects how wide the arms stretch."

Animations released alongside the new paper show how the Milky Way might look based on the new data, revealing the Outer and Scutum-Centaurus arms extending farther into intergalactic space, making our galaxy look more like a lopsided snail's shell than a perfect spiral.

These visualizations do not necessarily show the true shape of the galaxy, as the Sagitarrius arm and other minor galactic limbs have not been measured using the same methodology. However, the fact that the Perseus arm was not as distant as the other two GRB-illuminated limbs hints at a surprising asymmetry throughout our galaxy that cannot be easily explained.

The researchers are now on the hunt for more GRBs that can be used to map out the rest of our galaxy's shape and help us better understand what our cosmic neighborhood actually looks like. However, finding these cosmic explosions is easier said than done.

"We're relying on the universe to provide us with these events, and so far, over 25 years, we've only found a handful that we can use," study co-author Andrea Tiengo, an astronomer at Scuola Universitaria Superiore Pavia in Italy, said in the statement. "That said, we will continue to be on the lookout for more."

A deep-space telescope on a grand mission to make the largest-ever 3D map of the universe just peered into the star-filled heart of the Milky Way. In the new observations, shared Wednesday (June 24), the Euclid space telescope imaged the center of the Milky Way in extraordinary detail, showing off more than 60 million stars crowded in the galaxy's center.

The shiny new image from the European Space Agency (ESA) spacecraft will help astronomers confirm newfound exoplanets and use changes in starlight to measure those planets' masses as they orbit their parent stars, according to ESA scientists.

The image was taken in 26 cumulative hours in March 2025, across nine pointings of the telescope's visible-light camera toward the galaxy's center, also called the galactic bulge. Each viewpoint captured a slice of sky larger than the full moon. In a statement, ESA praised the performance of Euclid under challenging conditions.

"Designed to observe billions of faraway galaxies, the space telescope's visible-light camera is sensitive enough to tell apart individual stars in our super-crowded galactic bulge, without being blinded," agency officials wrote.

The mosaic image will help NASA's Nancy Grace Roman Telescope with its upcoming planet-hunting mission, after that observatory launches aboard a SpaceX Falcon Heavy rocket from NASA's Kennedy Space Center in Florida no earlier than Aug. 30.

One way the Roman telescope will search for new worlds is through microlensing, the same technique that can be used to examine exoplanets in the new Euclid image. Microlensing happens when one star passes in front of another from the perspective of an observer. The gravity of the closer-up star briefly bends and magnifies the light of the star behind it, allowing possibly unseen planets to pop up near that star.

"During the last 20 years, almost 300 exoplanets have been discovered using this technique, all with ground-based telescopes and all towards the centre of our galaxy," Jean-Philippe Beaulieu, who initiated the Euclid galactic bulge survey and co-led the Euclid Consortium's exoplanet working group, said in the ESA statement.

"This image from Euclid includes 51 known planetary systems ‪—‬ and it will assist in studying many more that will be found," added Beaulieu, who holds positions at the Paris Institute of Astrophysics and the University of Tasmania in Australia.

A cosmic time capsule

Euclid's observing window was too short to find a microlensing event, which requires more than 20 days of examining one star to watch for a planet's orbit and associated changes in the star's light. But Euclid's work did allow astronomers to measure already-known planets. And once newer planets are confirmed by other telescopes, the image will let astronomers look back to confirm those newfound worlds' masses.

"In 24 hours, Euclid has already captured the stars involved in all the future microlensing events that the Roman space telescope will detect, but before the stars and planets involved have aligned," Natalia Rektsini, a postdoctoral fellow at the Paris Institute of Astrophysics who led the release of Euclid's galactic bulge survey data, explained in the statement.

"Anyone who detects a microlensing event in the same region, for example with Roman, will be able from now on to use Euclid data as a time reference in the past and see how the stars looked before they overlapped," she added. "Since Euclid can clearly separate individual stars, one can then measure how fast they move over time, and use that information to confirm the existence of a planet and determine its mass. This would not be possible with data from one point in time."

How well do you know our home galaxy? Find out with our Milky Way quiz!

With the arrival of the summer solstice on June 21, stargazing becomes a late-night hobby. But June is one of the best months of the year to photograph the Milky Way from the Northern Hemisphere. As summer arrives, the brightest region of our galaxy — the galactic core — begins to climb into view in the southeastern sky. However, success will depend on timing, darkness and preparation.

The Milky Way is visible throughout the year, but its brightest and most photogenic section is best seen between May and September. In June, at midlatitudes, it becomes visible in the southeastern sky around 11:30 p.m. local time as true astronomical darkness begins, opening a roughly three-hour viewing window before the sky begins to lighten. Even so, you'll need a dark sky, which can be found using a light-pollution map or searching for a nearby Dark Sky Place, Dark-Sky Preserve (Canada) or Dark Sky Discovery site (U.K.).

A good way to find the Milky Way is to identify the three bright stars — Vega, Deneb and Altair — that make up the Summer Triangle, a famous and very large asterism that's prominent in the southeastern sky in June. The Milky Way will stream from Deneb to Altair and down to the southern horizon.

The best nights occur between the last-quarter moon on June 8 and a few nights after the new moon on June 14, when the moon will be out of the sky. That's particularly important in June because the moon hangs low in the south — exactly where the Milky Way's brightest section is.

How to take the best photos of the Milky Way

Once you're in position, you'll need a good astrophotography camera ‪—‬ a mirrorless or DSLR camera (preferably full-frame) with manual controls and RAW shooting capability. A sturdy tripod is also vital because exposures typically last between 10 and 25 seconds. Wide-angle lenses between 14 and 24 millimeters work particularly well because they capture more of the sky while allowing longer exposures before stars begin trailing.

With the camera in manual mode, try an aperture of f/2.8 (or the widest your lens can handle), an ISO of 3200-6400, and a shutter speed between 10 and 25 seconds, Capture the Atlas recommends. However, there are other considerations, such as manually focusing to ensure the stars are sharp (using live view or zooming in on an image to check) and employing a shutter delay to avoid camera shake. Then, you can use Photoshop or other post-processing software to adjust the contrast, highlights, color temperature and clarity to reveal spectacular details hidden within RAW files.

What many beginners ignore is the importance of composition. A close-up of the Milky Way will produce a disappointing image. Instead, think about striking foregrounds, such as coastal cliffs, abandoned buildings, lakes, rock formations, lone trees and people to create depth, scale and interest.

While June is an excellent month to begin Milky Way photography in the Northern Hemisphere, it will get even easier in July, August and September as the galaxy moves into the south and, ultimately, the southwest, before getting lost in the horizon once again around October. During that window, astrophotographers from the Northern Hemisphere often travel to dark-sky destinations farther south — such as the Canary Islands, Namibia, Chile, Australia and New Zealand — where darker skies and lower latitudes reveal more of the galaxy's bright core.

• Read more: Astrophotography settings 101

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

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

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

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

Photographer: Uroš Fink

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

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

"Galactic Gandalf"

Photographer: Evan McKay

Location: Wairarapa Coast, New Zealand​

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

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

"Sodium Milky Way"

Photographer: Julien Looten

Location: Very Large Telescope; Paranal, Chile​

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

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

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

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

"Firewater"

Photographer: Baillie Farley

Location: Grand Prismatic Spring, Yellowstone National Park, Wyoming

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

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

"Perseid Meteors Over Durdle Door"

Photographer: Josh Dury

Location: Durdle Door; Dorset, England

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

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

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

"Galaxy on the Rise"

Photographer: Anastasia Gulova

Location: Tenerife, Spain

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

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

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

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

"Salto del Agrio"

Photographer: Alejandra Heis

Location: Salto del Agrio; Caviahue, Argentina​

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

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

• Best astrophotography cameras
• Best lenses for astrophotography
• Best beginner astro cameras

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

Astronomers have identified some strange stars in the Milky Way that may have once belonged to a different galaxy.

By studying the chemistry of these stars and their motion close to the galactic disk, the researchers found that the stars' home galaxy, nicknamed "Loki," might have merged with our galaxy about 10 billion years ago.

Studying these stars could be "very important" in understanding the history of the Milky Way and the universe itself, lead author of the study Federico Sestito, an astrophysicist at the University of Hertfordshire in the U.K, told Live Science in an email. Sestito added that Loki may have been among "the very first small galaxies formed in the young universe."

Massive galaxies are not born whole. They are assembled over billions of years through mergers with smaller galaxies, which are sometimes absorbed. In the early universe, shortly after the Big Bang, matter clumped into clouds of gas that collapsed into the first primitive galaxies. These small systems then fell into one another, merged and gradually built up into the large structures we see today.

In the new study, published March 23 in the Monthly Notices of the Royal Astronomical Society, astronomers identified 20 old, very-metal-poor stars orbiting unusually close to the galactic disk — the flat, rotating region of the Milky Way where most stars, including the sun, reside — and examined whether a past merger might explain what they were seeing.

A chemical timestamp

The very first stars that formed in the universe were made of hydrogen and helium. It was only inside those early stars that hydrogen and helium fused into heavier elements, which astronomers call metals. These stars, when they eventually exploded, enriched the surrounding gas with those metals. Each successive generation of stars was therefore born from material slightly more enriched than the last.

As these small galaxies collided and merged, their stars, gas and dark matter became part of the growing young Milky Way. Because of this, computer simulations suggest that stars from the earliest mergers are expected to be found deeper inside the Milky Way today, while stars from galaxies that merged later are more likely to be scattered farther out in the galactic halo — a vast, spherical region that extends beyond the bright disk.

However, very few metal-poor stars have been found in the inner regions of the Milky Way to test this idea. So, when the team identified 20 metal-poor stars orbiting close to the galactic disk, they wondered whether the stars could be remnants of an ancient merger.

Hide and seek

The team identified these stars from an existing catalog of metal-poor stars. They observed each one using a powerful spectrograph at the Canada-France-Hawaii Telescope, which revealed their chemical abundances. Using precise positional data from the Gaia space telescope, they calculated the stars' distances and how they orbit in our galaxy.

Sestito said that "a mixture of information from the chemistry and the orbits of these stars" nudged them to examine the stars' origin. Rather than drifting through the halo of the galaxy where ancient, metal-poor stars have been mostly observed, these stars were tracing paths close to the Milky Way's disk within just 6,500 light-years from the sun.

"Usually, stars in the disk are metal-rich and younger, like the sun," he said, "while our stars [in the study] are old and very metal-poor (like in dwarf galaxies)."

Additionally, some of these stars were found moving in the same direction as the Milky Way's rotation, while others traveled in the opposite direction. But these two groups did not show any difference in their chemical abundances. Explaining how a single infalling galaxy could leave stars moving in opposite directions was also challenging.

The answer came from computer simulations of galaxy formation. If the merger happened early enough, when the young Milky Way was still lightweight and had not yet settled into a spinning disk, the infalling galaxy would have had enough freedom to scatter its stars in all directions.

"The early merging history of a large galaxy might be very chaotic, with various smaller systems merging together and dispersing their stars with many different orbits," Sestito explained. This scenario could produce both prograde and retrograde orbits, placing the merger event around 3 billion years after the Big Bang.

As a result, the simulations showed that a single dwarf galaxy swallowed by the young Milky Way more than 10 billion years ago, could have scattered its stars into exactly the orbital pattern observed today. The models also helped estimate the total mass of this galaxy to be around 1.4 billion solar masses.

The team nicknamed this infalling galaxy Loki.

"Loki, in the Norse mythology, is the God of mischief, and, as a trickster, his intents are hard to decipher," Sestito said. "Similarly, our accreted stars gave us some hard time in understanding their origin."

The search continues

Anirudh Chiti, an astrophysicist at Stanford University who was not part of the study, told Live Science that the new discovery shows promise.

"The chemical abundance analysis is intriguing, and part of the argument rests on the fact that the chemistry of the stars seems more clustered than those in the Milky Way halo," Chiti wrote in an email. "This is a nice example of the kind of discovery that those samples could turn up or verify."

Still, the new findings fall short of certainty. Sestito acknowledged that more observations are needed to confirm them.

"Our work is surely limited in terms of the number of observed stars," Sestito said. Observing stars with high-resolution spectroscopy is time-intensive — each star requires around four hours of telescope time, which is why the current sample is small.

Because researchers are still in the early stages of exploring the chemical signatures of the lowest-metallicity stars in the Milky Way disk, it remains plausible that these stars belong to a subgroup of stars or substructure within the Milky Way, Chiti noted. "I'm looking forward to what future work mapping the chemistry of large samples of very metal-poor stars in the Milky Way disk may show," he said.

To confirm the nature of Loki, the team would need to observe its stars and other non-Loki targets with the same telescope setup to better understand the differences between this system and other parts of the Milky Way halo.

With upcoming advanced spectroscopic facilities, astronomers will be able to observe hundreds of stars with available high-quality data on their trajectories and chemical abundances. Sestito thinks the search should not be limited to the halo. The hidden systems in the inner regions of the galaxy could hold clues to the primitive galaxies of the young universe, though detecting them in the crowded disk would be challenging.

Interstellar comet 3I/ATLAS is up to 12 billion years old and unlike anything found in our solar system, new James Webb Space Telescope (JWST) observations suggest.

Comet 3I/ATLAS became a celestial celebrity last year after the interstellar visitor was discovered hurtling through our cosmic neighborhood. Not long after, online speculation suggested that the space rock could be an alien spacecraft. However, most astronomers are confident that 3I/ATLAS is a comet from an unknown star system.

Now, new preliminary findings from a study posted to the preprint server Research Square, which are still under peer review, suggest the comet formed in a cold and distant region of the Milky Way around 10 billion to 12 billion years ago. That would make comet 3I/ATLAS more than twice as old as Earth (4.5 billion years old) and our solar system (4.6 billion years old), and at its upper range, not far off the ages of our Milky Way galaxy and the universe itself (about 13.6 and 13.8 billion years old).

Researchers already knew from the comet's speed and trajectory that it was potentially the oldest comet ever seen. Previous estimates put the comet's age at somewhere between 3 billion and 11 billion years old. The new findings further narrowed down the comet's age and origin by looking at isotope measurements taken by JWST when the comet flew past Earth in December 2025.

"They show that 3I/ATLAS isotopic composition is very different from solar system comets and suggest that it likely formed 10-12 billion years ago," Romain Maggiolo, a research scientist at the Royal Belgian Institute for Space Aeronomy who was not involved in the study, told Live Science in an email. "In other words, 3I/ATLAS formed in a stellar environment different from ours, not only somewhere else in space, but also at a much earlier time in the history of the Milky Way."

Comet 3I/ATLAS is only the third interstellar object ever recorded in our solar system. The space rock, which Hubble Space Telescope observations suggest is somewhere between 1,400 feet (440 meters) and 3.5 miles (5.6 kilometers) wide, zoomed into our solar system at around 137,000 mph(221,000 km/h) last year before slingshotting around the sun.

After reaching its closest point to our star, known as perihelion, on Oct. 29, 2025, the comet then made its closest approach to Earth on Dec. 19, when it came within about 168 million miles (270 million km) of our planet. JWST made the observations that have been analyzed in the new study a few days later on Dec. 22.

A relic from the ancient universe

Comets heat up as they fly closer to stars, which causes ice on their surfaces to sublimate into gas. By studying the composition of this gas, researchers can start to figure out what they're made of and the conditions in which they formed.

The authors of the new preprint looked at the ratio of isotopes, or versions of elements, in material outgassed by 3I/ATLAS. They found that the comet's water is more enriched in deuterium, a heavier hydrogen isotope, than any previously studied comet, while its ratio of carbon isotopes also exceeded levels normally seen in our solar system.

The results offer clues to what conditions may have been like in whatever ancient planetary systems forged the comet in the early years of the Milky Way.

"If 3I/ATLAS is indeed as old as this study suggests, the large amounts of volatile molecules it contains indicate that rich prebiotic chemistry may already have been occurring in star-forming regions very early in the history of our Galaxy," Maggiolo said.

The results also indicate that the comet formed in a cold environment that was around 30 kelvins (minus 406 degrees Fahrenheit, or minus 243 degrees Celsius), likely in a dense and well-shielded protoplanetary disk, according to the study.

While the study is still in the preprint stage, Maggiolo, who has studied comet 3I/ATLAS as part of his own research, didn't have any major concerns about it. The new measurements help researchers "better understand this interstellar messenger," he said.

Josep Trigo-Rodríguez, the research principal investigator of the Asteroids, Comets and Meteorites research group at the Institute of Space Sciences (CSIC/IEEC) in Spain who has previously identified erupting "ice volcanoes" on comet 3I/ATLAS, described the new findings as a good compilation of scientific results, using different techniques from well-recognized experts.

"This manuscript exemplifies that interstellar comets are unique bodies that are able to sample remote regions of our Milky Way galaxy," Trigo-Rodríguez told Live Science in an email.

There's a good chance that researchers will never know which star system birthed comet 3I/ATLAS. The comet has likely been traveling through space for billions of years and has come a very long way in that time. Maggiolo's own research has found evidence that the object is extremely irradiated, with all that time in space exposing it to cosmic rays that could have fundamentally altered its chemical composition, making its origins more difficult to decipher.

"The isotopic composition of the material outgassed by 3I/ATLAS provides a crucial new piece of the puzzle," Maggiolo said. "But the puzzle is far from being complete!"

Finding those puzzle pieces is a race against time for astronomers, as comet 3I/ATLAS is now hurtling out of the solar system. It's currently passing Jupiter, where it is expected to make its closest approach on Sunday (March 15). The comet will come within about 33 million miles (54 million km) of the gas giant — much closer than it got to Earth.

The interstellar traveller will then continue its journey away from us, crossing Saturn's orbit in July, Uranus' orbit in April 2027 and Neptune's orbit in March 2028. You can track the comet using NASA's Eyes on the Solar System simulation of the comet's trajectory.

Thousands of sun "twins" spotted by a space telescope could shed new light on how our star came to host at least one life-friendly world — and a big stellar migration was involved.

Researchers used data from the now-retired Gaia space telescope, a European Space Agency observatory that charted the movements of millions of stars in high definition from 2014 to 2025. The telescope yielded 6,594 stellar "twins" — stars with similar ages, temperatures, compositions and surface gravities as the sun — about 30 times more than previous surveys had found.

Moreover, most of these sibling stars were spotted in our sun’s nearby neighborhood. Collectively, the samples tell of a mass movement of stars out of the galaxy's crowded center over billions of years.

"By studying a large population of these solar twins, we found evidence suggesting that many solar twins of the same age migrated through the Milky Way around the same time as the sun, giving us new clues about when and how the sun moved from its birthplace to its current location," Daisuke Taniguchi, an assistant professor at Tokyo Metropolitan University who co-led the team with Takuji Tsujimoto from the National Astronomical Observatory of Japan, told Live Science in an email.

Migration of the stars

Taniguchi led one of the studies published Thursday (March 12) in the journal Astronomy & Astrophysics and co-authored the other. Together, the studies propose that when the central "bar" of stars and gas in the Milky Way formed, this process both enhanced star formation and sent a number of stars into other regions of the galaxy. This formation and "migration," as the researchers called it, also included the sun.

“We propose that the formation of the Milky Way's central bar enhanced star formation and also triggered large-scale migration, leading to the formation and outward migration of the sun—and many solar twins,” Taniguchi said.

Previous studies had noted that, based on its composition, the sun must have moved by at least a few thousand light-years out of the galaxy's center. But the issue is that the bar in the Milky Way serves as a "barrier" to stars moving so far away, some models show. The solution to this issue is to propose that the barrier formed only after all of the stars left the region, the scientists suggested.

"This scenario, if correct, could also provide new constraints on the epoch of the galactic bar formation," Taniguchi said. The researchers suggested that our galaxy's central bar took shape about 4 billion to 6 billion years ago. (The sun itself is roughly 4.5 billion years old, which puts it squarely within that time frame.)

Taniguchi pointed out that in the center of the Milky Way, supernovas and other kinds of "energetic events" tend to occur more frequently than in other regions — in part due to the extreme population density of stars there. This would make the inner parts of the galaxy potentially hostile to life. And that has implications for how life arose on Earth, as well as potentially other planets in the galaxy.

"If the sun migrated outward relatively soon after its birth, as our study suggests, the solar system may have spent most of its history in the quieter outer disk," Taniguchi said. "In other words, the sun may not have arrived in a life-friendly environment purely by chance, but rather as a consequence of the formation of the galactic bar."

Milky Way quiz: How well do you know our home galaxy?

Scientists have unveiled the largest, most-detailed-ever map of the chaotic gas clouds at our galaxy's center. The resulting image could take years to analyze but promises to help unravel the mysteries of how the earliest stars lived and died right after the Big Bang.

The new observations, taken with the Atacama Large Millimeter/submillimeter Array (ALMA) radio telescope in Chile, cover 650 light-years' worth of structures surrounding the Milky Way's central black hole, deep within the constellation Sagittarius. This region is known as the Central Molecular Zone (CMZ) for its many clouds of dense molecular gas and is thought to closely mirror the compact and chaotic conditions of the earliest galaxies in the universe.

The full image covers a parcel of the sky about as wide as three full moons — the largest image ALMA has ever produced since starting operations in 2013. This ultra-detailed view includes everything from gargantuan clouds of supersonic gas to individual stars whipping around the galactic center and is already turning up some "rare and enigmatic" structures that defy explanation.

By studying the movement, velocity and chemical composition of the gas within the CMZ, scientists hope to better understand the extreme conditions that spurred the evolution of the Milky Way, as well as the ancient galaxies that filled the infant universe.

"It's a place of extremes, invisible to our eyes, but now revealed in extraordinary detail," Ashley Barnes, an astronomer at the European Southern Observatory (ESO) and a member of the team behind the new observations, said in a statement. And with even more powerful telescopes under construction in the region, "in many ways, this is just the beginning," Barnes added.

Zone of chaos

Roiling around the supermassive black hole Sagittarius A*, the CMZ is a sprawling collection of colliding clouds, supersonic gas highways, and hyperactive stars that grow fast and die young. The region contains most of the dense gas in our galaxy — about 80%, according to the Harvard and Smithsonian Center for Astrophysics — and is the hottest, densest and most turbulent neighborhood in the Milky Way.

The turbulent flow of molecular gas supercharges star formation in parts of the CMZ while leaving other areas perplexingly empty. Scientists hope to understand how the large-scale processes that push matter through the CMZ govern the evolution of small-scale objects, like individual stars and gas clouds.

Enter ACES — the ALMA CMZ Exploration Survey, which brings together more than 160 scientists from 70 institutions around the world to study the mysterious CMZ. In a series of five papers accepted for publication in the journal Monthly Notices of the Royal Astronomical Society, the ACES team shared the survey's preliminary findings and how they could advance our understanding of the galactic center over the coming years.

The team noted that, by studying the various wavelengths of light emitted by gas in the CMZ, the survey identified more than 70 types of molecules tumbling through the galactic center. These include both simple molecules, such as silicon monoxide, and more complex organic ones, like ethanol and methanol, the researchers said.

By zooming in on specific regions of the image, the team could also see how specific processes — such as the eruption of shock waves released during massive gas cloud collisions — affected the heat, motion and chemical composition of different areas in the CMZ. All of this will eventually help scientists build a 3D map of the CMZ, revealing how different substructures are interconnected and how the large-scale flow of matter leads to star formation and destruction.

"The CMZ hosts some of the most massive stars known in our galaxy, many of which live fast and die young, ending their lives in powerful supernova explosions, and even hypernovae," ACES team leader Steven Longmore, a professor of astrophysics at Liverpool John Moores University, said in the statement.

Relics and rarities

The preliminary findings also describe some unusual discoveries. One anomaly the team briefly noted is a structure called the Millimeter Ultra-Broad Line Object (MUBLO). The compact, dusty object appears only at millimeter wavelengths of light and is otherwise invisible to X-ray, infrared and radio telescopes.

Filled with fast-moving gas, the MUBLO shows some traits similar to the active young stars expected to populate the galactic center — but, so far, the object's characteristics don't match any other known structure in space, the team added.

Digging into anomalies like MUBLO and how they fit into the larger-scale structure of the CMZ could open new doors to understanding the extreme environments of the ancient universe that are too far away to observe directly.

"By studying how stars are born in the CMZ, we can also gain a clearer picture of how galaxies grew and evolved," Longmore added. "We believe the region shares many features with galaxies in the early Universe, where stars were forming in chaotic, extreme environments."

Editor's note: This article was updated on Feb. 25 at 10:30 a.m. to include an additional image of the CMZ.

Is the ultradense core of a gigantic star lurking in the center of the Milky Way?

Scientists think they may have found just that: the signal of a pulsar, a rapidly rotating ancient star core, in the heart of our galaxy. The rare discovery could be used to test the predictions of Einstein's general relativity.

Pulsars, a kind of neutron star, are known as "cosmic lighthouses" because they send out beams of radio emissions with every spin, and these beams occasionally strobe past Earth. The suspected pulsar whips around on its axis every 8.19 milliseconds and is located near Sagittarius A*, a supermassive black hole with the mass of 4 million suns embedded in the Milky Way's center.

The researchers published their findings Monday (Feb. 9) in The Astrophysical Journal. The work was led by Karen Perez, a postdoctoral researcher at the SETI Institute who was a doctoral student at Columbia University at the time of the research.

"We're looking forward to what follow-up observations might reveal about this pulsar candidate," Perez said in a statement. In particular, she added, the researchers hope to use the pulsar to probe general relativity.

Testing the rules of the universe

General relativity, first proposed by Albert Einstein, proposes that gravity is not a force in nature but a property of how space-time curves.

A nearby pulsar in the Milky Way would let researchers learn about "precision measurements of the space-time around a supermassive black hole," the statement noted. That's because pulsars rotate so rapidly that they are sensitive to the subtle gravitational pulls of massive neighboring objects, like other stars.

The pulsar's rotation could then, in theory, produce "anomalies" in the pulses of light that it sends toward Earth, said study co-author Slavko Bogdanov, a research scientist at the Columbia Astrophysics Laboratory.

"In addition, when the pulses travel near a very massive object, they may be deflected and experience time delays due to the warping of space-time, as predicted by Einstein's general theory of relativity," Bogdanov added.

Researchers detected the suspected pulsar through Breakthrough Listen, a scientific research program that aims to find signals of civilizations beyond Earth. The new findings came from the Breakthrough Listen Galactic Center Survey, which, as the name suggests, hunted for signals coming from the center of the Milky Way.

Breakthrough Listen released all of the data publicly, the researchers added, "allowing researchers worldwide to pursue independent analyses and complementary science cases."

Further research is needed to confirm whether the signal really was a pulsar, or if it came from some other exotic radio source.

Milky Way quiz: How well do you know our home galaxy?

Astronomers have solved the mystery of how some stars stay youthfully bright and blue, despite being almost as old as the universe itself: They cannibalize their stellar siblings.

Known as blue straggler stars, these age-defying celestial objects have mystified astronomers for more than 70 years. "Blue stragglers are anomalously massive core hydrogen-burning stars that, according to the theory of single star evolution, should not exist," researchers wrote in a paper published Jan. 3 in the journal Nature Communications.

To investigate these puzzling stars, researchers used the James Webb Space Telescope (JWST) to analyze 48 galactic globular clusters and more than 3,400 blue straggler stars in the Milky Way. Their observations revealed that these "forever young" stars stay youthful by siphoning the gas from their partners, like stellar vampires. This fuel injection allows the vampire stars to shine more brightly, and to appear more blue and youthful, long after they should have started fading away.

Searching for age-defying stars

Scientists previously posited that blue stragglers can form in two ways: through violent collisions between two stars, or through more subtle interactions in binary systems as pairs of stars orbit each other and trade gas.

The team found that the latter scenario is more likely.

Galactic globular clusters provide the perfect place to study stellar interactions between gas-siphoning binary systems. These spherical clusters contain thousands or millions of stars, held together by their collective gravity. With so many stars inhabiting a region only tens or hundreds of light-years across, clusters are among the most dense stellar environments in the cosmos. Therefore, they host many stellar collisions and plenty of binary systems.

Clusters are also incredibly ancient. "Their age is of the order of 12 [billion years], hence comparable to the age of the Universe," which is 13.8 billion years old, Francesco Ferraro, lead author of the study and an astronomy professor at the University of Bologna in Italy, told Live Science via email. "In fact they are the oldest population in our Galaxy." This means the single stars in each cluster hosting the blue stragglers formed at the epoch of galaxy formation.

Older stars also emit different wavelengths of radiation. So the researchers utilized JWST's ultraviolet filters to distinguish blue stragglers from their elderly cluster-mates — because hotter -- younger stars emit more radiation at shorter wavelengths than older, redder populations that emit poorly in this part of the electromagnetic spectrum.

A surprising stellar scenario

Perhaps counterintuitively, the researchers found that blue stragglers are rarer in dense stellar environments, even though these regions are more likely to facilitate interactions between stars. Instead, stragglers are significantly more common in calm, low-density regions where stars are spaced farther apart and "fragile binary systems are more likely to survive."

The researchers used an established, quantitative measure that relates the number of blue stragglers to the host cluster's characteristics, like luminosity. This measure revealed that blue straggler populations vary greatly, from three to 58 blue stragglers per unit of luminosity — equivalent to the brightness of 10,000 suns. Accordingly, luminosity is related to a cluster’s overall mass and, therefore, its density.

Using that same measure, the researchers calculated that the number of regular stars in a cluster remains relatively constant. This suggests that stragglers and binary systems are especially sensitive to the density of their environments.

"Crowded star clusters are not a friendly place for stellar partnerships," study co-author Enrico Vesperini, an astronomer at Indiana University, said in a statement. "Where space is tight, binaries can be more easily destroyed, and the stars lose their chance to stay young."

Therefore, dense environments, such as those nearer the centers of clusters, may not be the stellar speed-dating venues they were assumed to be. The gravitational influences from large stellar populations create a cosmic-bumper-car-like effect that disrupts binary systems early in their evolution, before they can turn into blue straggler stars. As a result, the formation and survival efficiency of stragglers is 20 times higher in calmer, low-density environments, the researchers found.

A new way to understand stellar evolution

In addition to solving an astronomical mystery, this study offers a "new way to understand how stars evolve over billions of years," study co-author Barbara Lanzoni, an astronomer at the University of Bologna, said in the statement.

But after billions of years, blue stragglers may not get to live out their quiet lives in peace. Because they are significantly more massive than their sibling stars, they are more likely to sink to the core of their clusters through a process called dynamical friction. Although this is unfortunate for these calm-loving stars, astronomers can then use them as a "dynamical clock" to extrapolate a cluster's age based on the distribution of its blue stragglers.

Finally, these sprightly, fresh-faced stars highlight a dynamic stellar balance. Had they been born more massive, they would have died long ago as supernovas or white dwarfs. Their modest size, below 0.8 solar masses, have allowed them to survive long enough to renew their lifespans — at the cost of consuming their siblings.

Stunned astronomers have discovered a zombie star relatively near Earth that is inexplicably emitting a persistent, rainbow-like shock wave as it speeds through the Milky Way. The undead stellar remnant, which is currently devouring its companion star, has left researchers scratching their heads.

Every star in the Milky Way is constantly spinning around the supermassive black hole at the heart of our galaxy, dubbed Sagittarius A*. Most of these stars, including the sun, are preceded by a bow shock, which pushes material around the star, similar to the waves generated around the bow of a ship as it moves through the water. These bow shocks are created by outflowing gas and dust from the star, which collides with and pushes against the interstellar medium — the leftover matter and radiation that exists in the gaps between stars.

Other, smaller and less active stars do not have bow shocks because they lack outflowing material, meaning they offer up little to no resistance against the interstellar medium. Some of the best examples of bow shock-free stars are white dwarfs, the shriveled husks left behind from the cores of massive stars that have died in violent supernova explosions.

But in a new study, published Jan. 12 in the journal Nature Astronomy, a group of astronomers discovered a white dwarf, named RXJ0528+2838, that is surrounded by a bow shock. The rule-breaking star is located roughly 730 light-years from Earth and is part of a binary system, alongside another sun-like star that is slowly being devoured by the cosmic zombie.

Using observations from the European Southern Observatory's (ESO) Very Large Telescope (VLT) in Chile, the study team mapped out this surprising shock wave, which extends around 4,000 Earth-sun distances from the stellar pair and is at least 1,000 years old. Images also show that the bow shock contains a dense cloud of multicolored gas and dust, or a nebula, which only adds to its mystery.

"We found something never seen before and, more importantly, entirely unexpected," the study's other co-lead author Simone Scaringi, an astronomer at Durham University in the U.K., said in an ESO statement.

"Our observations reveal a powerful outflow that, according to our current understanding, shouldn’t be there," added the study's other co-lead author Krystian Iłkiewicz, a postdoctoral researcher at Poland's Nicolaus Copernicus Astronomical Center. "This discovery challenges the standard picture of how matter moves and interacts in these extreme binary systems."

Given that RXJ0528+2838 is part of a binary star system, the obvious explanation for its bow shock is that its partner star is outflowing material that is colliding with the interstellar medium. However, the researchers strongly believe this is not the case.

In a binary system like this, the most massive star — which, in this case, is the superdense white dwarf — slowly devours its partner by pulling material from its surface. This means that RXJ0528+2838's partner does not outflow like similar stars of its size, because the white dwarf also hoovers up any outflowing material.

This process normally leaves a disk of excess stellar material circling the more massive star, which could also generate a similar type of stellar outflow. However, there is no visible disk around RXJ0528+2838, which strongly suggests this isn't happening.

"The surprise that a supposedly quiet, diskless system could drive such a spectacular nebula was one of those rare 'wow' moments," Scaringi said.

Instead, the researchers suspect that RXJ0528+2838's mysterious "outflow" may be tied to its immensely strong magnetic field. This invisible energy source is also the reason why the white dwarf has no disk, because it is sucking up everything around it, similar to a black hole.

However, the researchers cannot identify the exact mechanism by which the magnetic field acts to replicate the effects of a stellar outflow, which they have dubbed the "mystery engine."

The researchers are now on the hunt for similar systems that may offer clues as to what is going on with RXJ0528+2838. Luckily, ESO's upcoming Extremely Large Telescope (ELT) — the successor of VLT, which is due to go online as early as 2028 — will likely help with this.

ELT will allow astronomers "to map more of these systems as well as fainter ones and detect similar systems in detail, ultimately helping in understanding the mysterious energy source that remains unexplained," Scaringi said.

Roughly 4.5 million years ago, the sun passed remarkably close to two intensely bright stars whose radiation flooded nearby space — and the encounter left a ghostly scar that astronomers can still detect today, according to a new study.

The research team says the close pass helps to solve a decades-old mystery of why the space around our solar system is far more energized than models predict, including why it contains a surplus of ionized helium.

Using computer models to rewind the paths of stars near the sun, a team led by University of Colorado Boulder astrophysicist Michael Shull found that two blue-white stars, Beta Canis Majoris and Epsilon Canis Majoris, passed within 30 light-years of the sun about 4.5 million years ago.

Today, the stars mark the front and rear legs of the constellation Canis Major (the Great Dog), more than 400 light-years from the solar system. But roughly 4.5 million years ago, when the stars brushed past the solar system, they were younger, hotter and brighter. Their passage also may have overlapped with the time when Lucy — a remarkably complete fossil of an early human ancestor discovered in Ethiopia in 1974 — walked the Earth.

"They weren't headed straight toward us...but that's close," Shull told Live Science. "If Lucy and her friends had looked up and had noticed the stars, the two brightest stars in the sky would have been not Sirius, but Beta and Epsilon Canis Majoris."

The findings were published Nov. 24 in The Astrophysical Journal.

A lingering mystery

Today, the solar system drifts through a diffuse patchwork of more than a dozen nearby wisps of gas and dust called the local interstellar medium, made primarily of hydrogen and helium and extending roughly 30 light-years from the sun.

Astronomers think these clouds were sculpted over several million years by shock waves from exploding stars in the Scorpius-Ophiuchus region, a rich cluster of massive stars about 300 light-years from Earth, which compressed interstellar gas into the thin local clouds seen today.

Observations dating back to the 1990s, including from NASA's now-retired Extreme Ultraviolet Explorer space telescope, revealed that this region is unusually ionized. Helium atoms, in particular, have been stripped of their electrons at nearly twice the rate expected relative to hydrogen.

That imbalance has puzzled astronomers, because helium requires more energetic radiation to ionize than hydrogen does. This makes its elevated ionization difficult to explain with the sun's radiation alone, which does not extend that far beyond the solar system.

To investigate the mystery, Shull and his colleagues calculated the properties and ultraviolet output of Beta and Epsilon Canis Majoris, using measurements from the European Space Agency's Hipparcos satellite, which mapped the positions of more than a million stars across a four-year mission that ended in 1993.

Knowing how far away the two stars are today — about 400 light-years — and how fast they are moving allowed the team to trace the stars' paths backward through time to reconstruct their close pass by the solar system roughly 4.5 million years ago.

"It's like a dance floor"

The team's models show that the wispy local clouds would have been intensely ionized by the two stars' radiation — at levels up to 100 times stronger than those seen today. Over time, the gas would have slowly returned to a more neutral state through a process called recombination, in which free electrons reattach to ions and become atoms.

"It's like a dance floor," Shull told Live Science. "You've got protons and electrons dancing around, and sometimes they're dancing together and sometimes they're popping apart."

But that process takes time, and continued exposure to radiation from other sources continues to keep the gas partially ionized, Shull said. Astronomers had previously identified other sources of ionizing radiation, including three nearby white dwarf stars — G191-B2B, Feige 24 and HZ 43A — compact stellar remnants that are known to emit strong ultraviolet light. Researchers also pointed to the Local Bubble — a vast, supernova-blown region of hot gas that extends about 1,000 light-years around the solar system.

"More energetic photons preferentially ionized helium," he said. "That's the bottom line."

The pieces come together

Although astronomers have had reliable stellar motion data for decades, Shull said the problem became solvable only recently. Advances in ultraviolet and X-ray observations made possible by suborbital rocket flights, along with improved models of stellar evolution and atmospheres — and the computing power needed to run them — finally allowed researchers to connect the dots.

"The problem was ripe in the sense that all the pieces of the puzzle of the mystery were starting to come together," Shull said.

The findings also may have implications closer to home. The local clouds help shield the planet from high-energy particles that roam the galaxy and that scientists suspect could erode Earth's ozone layer.

The sun, however, is not expected to remain inside these clouds indefinitely. As it drifts onward through the galaxy, researchers estimate it could exit the protective region in as few as 2,000 to a few tens of thousands of years. "Then, we're going to be in for a big dose of radiation," Shull said.

Looking ahead, Shull said that understanding how atoms in the wispy local clouds shifted between more charged and more neutral states as radiation waxed and waned while the two stars approached, passed by and moved away from our solar system remains part of a larger puzzle researchers are still assembling. "The problem isn't completely solved," Shull said, "but I think we have the right track."

A new study suggests that a NASA telescope may have made the first-ever observation of elusive dark matter, the invisible and mysterious substance that makes up most of the matter in the universe. However, scientists, including the study author, caution that more research is needed to understand the finding.

NASA's Fermi Gamma-ray Space Telescope, which studies high-energy wavelengths of light known as gamma-rays, spotted emissions in the center of the Milky Way that may be associated with particles linked with dark matter, according to the study, published Tuesday (Nov. 25) in the Journal of Cosmology and Astroparticle Physics.

"If this is correct, to the extent of my knowledge, it would mark the first time humanity has 'seen' dark matter," Tomonori Totani, an astronomy professor at the University of Tokyo and the sole author of the study, said in a statement.

But the study cautions that independent confirmation of this signal must be obtained — not only from the Milky Way but also "from other objects or regions" with similar properties. Similarly, theoretical physicist Sean Tulin, an assistant professor of physics and astronomy at York University in Toronto, told Live Science he would like an independent analysis of the work because it's not the first time such claims have been made using the Fermi telescope.

A prominent example is the "galactic center excess," a source of unexplained gamma-ray light discovered with Fermi data in 2009. After nearly two decades of further research, scientists continue to debate whether the excess is the result of dark matter or more conventional astronomical sources, such as fast-spinning stars known as pulsars.

WIMPs in the cosmos

Dark matter is a nonluminous substance believed to make up most of the matter in the universe. So far, it has been traced only through its gravitational effects on other objects. For example, in a seminal 1933 paper, astronomer Fritz Zwicky stated that faraway galaxies were moving around each other faster than predicted based on the visible matter that could be seen with telescopes. The gravitational pull of dark matter was pegged as the likely reason.

There have been several theories about what dark matter includes, but most astronomers today suggest it is made of subatomic particles. Totani's study centers on a popular particle suggestion, the weakly interacting massive particle (WIMP).

WIMPs fall outside the widely used Standard Model of particle physics, which successfully shows (for the most part) how the building blocks of matter interact with each other. But the model does not account for the force of gravity or the existence of dark matter, according to CERN.

WIMPs are heavier than protons, according to the statement, and WIMPs hardly interact with other types of matter. But when two WIMPs crash into each other, these particles would be destroyed and energetically unleash other particles during the collision, including photons of gamma-rays.

Dark matter, or no?

To search for the gamma-rays associated with WIMP collisions, many studies have focused on clusters of dark matter, such as the center of our Milky Way galaxy. Data obtained from 15 years of observations with the Fermi telescope showed gamma-rays "in a halo-like structure toward the center of the Milky Way galaxy" that "matches the shape expected from the dark matter halo."

These gamma-rays were extremely energetic, with a photon energy of 20 gigaelectron volts (20 billion electron volts). According to the statement, this energy "matches the emission predicted from the annihilation of hypothetical WIMPs," as well as the frequency of WIMP annihilation.

However, Tulin pointed out that the signal shows up only when you remove the background of "all sources of energetic photons coming from the Milky Way," including from its center and its disk. Some background energy is also present from "Fermi bubbles" — two huge zones of gas and cosmic rays that loom over the Milky Way.

All studies looking at energy sources from the Milky Way need to model that background noise and then subtract that to "reveal the underlying signal," Tulin said. "What you infer for the signal depends very carefully on what you subtracted off of the background. … There's a risk of being tricked if you subtract something off incorrectly."

Aside from questions about the background, the signal could depend on the type of dark matter particle being discussed, Tulin said. "What that means is, what is the model for that dark matter particle?" he said. "What is its mass? What are its fundamental properties? What are its different interactions?"

However, the model of annihilation for a standard WIMP is "perfectly reasonable" with the signal Totani observed, Tulin said, with the assumptions that the study is observing WIMPs under the model we understand and the background is subtracted correctly.

Tulin (who had access to a study preprint when speaking with Live Science) added that despite his cautions, the findings "would be a remarkable thing if it was due to dark matter … not just for the future of the astronomical observations, but this type of dark matter particle could be tested and discovered in all sorts of different experiments, like underground labs and in colliders."

That said, "no one is really staking their house on this being the one time that it turned out to be correct," Tulin said of the new study. "We've seen a lot of anomalies come. A lot of anomalies go. Some anomalies have stuck with us, and still require further exploration."

Look into the night sky, and it might seem like space is a vast expanse of darkness. But are any regions darker than others? What's the darkest place in the solar system and, on a grander scale, the universe?

In short, the answer isn't straightforward, and it depends on whom you ask, experts told Live Science.

True darkness, the blackest black, is surprisingly rare and hard to pinpoint. This is because there is a lot of dust in the cosmos: Dust scatters light, making space glow far beyond stars, Marc Postman, an astronomer at the Space Telescope Science Institute (STScI) in Baltimore, told Live Science. As a result, there is a background glow that permeates much of the universe. (The color of the universe is actually "cosmic latte," a beige shade not too far off white.)

Darkness also "depends on how you define it," Andreas Burkert, a theoretical astrophysicist at the University of Munich, told Live Science. The visible light spectrum illuminates some places in the universe with light. However, other wavelengths on the electromagnetic spectrum, like gamma rays and ultraviolet light, touch almost everything. This means that space, when viewed in the full electromagnetic spectrum, is quite luminous.

Low albedos

If you consider only visible light, there are some exceedingly dark places in space. A number of factors contribute to this darkness.

Firstly, cosmic objects can be made of light-absorbing material, making them appear very dark. Scientifically, this is known as albedo, or the amount of light reflected off a surface. A perfect mirror, for instance, would reflect 100% of the light directed at it and have an albedo of 1, while charcoal has an albedo of 4%.

The nucleus of comet Borrelly (also called 19P/Borrelly) is one of the darkest spots in our solar system, according to the Guinness Book of World Records. The 5-mile-long (8 kilometers) comet is made up of dust and ice that reflects less than 3% of sunlight, based on an image taken in 2001.

Similarly, the darkest known exoplanet in the universe, TrES-2 b, reflects less than 1% of light, thought to be because of high amounts of sodium vapors and gaseous titanium oxide in the atmosphere. In contrast, Earth reflects about 30% of the sun's light.

Black holes, too, are dark because they capture light that crosses the event horizon. But interestingly, "that doesn't mean that there is no light," Burkert said. "It simply is trapped." As a result, "when you enter the black hole, it's actually extremely bright," he explained.

Blocking light and distant objects

Darkness can also exist if something is blocking light from nearby stars. For example, some craters on our moon, located at the poles, never see the sun's light. These places are very dark because they are in "permanent shadow," Postman said. The shadowed craters on Pluto can be quite dark as well, because of their distance away from the sun.

Far beyond that, dense dust clouds, called molecular cores or Bok globules, are also thought to be pitch black. They look like "a hole in the sky," Burkert said. This is because the globule, made up of a mix of molecular hydrogen, carbon oxides, helium and silicate dust, blocks nearly all visible light from surrounding stars, making them disappear. However, this light-blocking is not as profound in the infrared spectrum, Burkert noted, who has studied Barnard 68, a globule around 500 light-years away from Earth.

Finally, there are pockets of the sky that are dark simply because they are far away from any light source. These places were documented by NASA's New Horizons telescope, an instrument sent to take photos of the galaxy's outer corners.

Based on a 2021 paper published in The Astrophysical Journal, these faraway regions are very dark. "On average, the sky out there is 10 times darker than it is near the Earth," said Postman, who was a co-author on the study. However, these regions still had light from the background glow of the cosmos.

Burkert noted the Earth sits in a relatively dark cavity in the Milky Way, which uniquely allows us to have an unobstructed view far into space.

"We sit in the middle of this big bubble, and so we can see a lot of stars," Burkert said. "If we would not be in the bubble, maybe astronomy would not have developed. So [darkness] is a very relevant, I think, important idea and question."

We cannot see or image the entire Milky Way galaxy, because we are located inside it. From Earth, we can observe only a portion of the galaxy, and when we look up at the dark, clear night sky from a place free of light pollution, the Milky Way appears as a complex, busy band of stars and dust. This is our edge-on view of the dense galactic plane of our galaxy. And that's just the visible light view.

Imagine the sheer extravagance of this structure were it to be captured in radio colors, which can penetrate the thick clouds of dust and gas that block visible wavelengths. Fortunately, astronomers have now successfully captured a stunning view of the galactic plane as seen from the Southern Hemisphere using a wide range of radio wavelengths.

Silvia Mantovanini, a PhD student at Curtin University in Australia, took nearly 40,000 hours to compile the data from two surveys called the GaLactic and Extragalactic All-sky MWA (GLEAM) and GLEAM eXtended (GLEAM-X). The GLEAM and GLEAM-X surveys, conducted using the Murchison Widefield Array telescope, yielded abundant data over 28 nights in 2013 and 2014, and 113 nights from 2018 to 2020.

Thanks to significant improvements in sky coverage, resolution and sensitivity, the new image provides twice the resolution, has 10 times the sensitivity and covers double the area of the previous GLEAM image released in 2019, according to a statement from the International Centre of Radio Astronomy Research (ICRAR). Researchers say that only the SKA-Low telescope, an array of tens of thousands of radio antennae set to be completed next decade, can surpass this level of sensitivity and resolution.

This extensive survey view is the largest low-frequency radio color image of the Milky Way ever created. Since most of the imaged region had never been observed at these frequencies, this galactic landscape marks a significant milestone, the researchers said.

The low-frequency radio waves revealed remnants of exploded stars and regions of ionized gas where new stars are forming. The "colors" of radio light captured in the image help astronomers distinguish between different objects in the sky. The large red bubbles reveal dead stars and their expanding shells, whereas the compact blue regions are where new stars are born.

The surveys contain more than 98,000 radio sources — including pulsars, planetary nebulae and compact star-forming regions — across the Milky Way's plane as seen from the Southern Hemisphere. The new image captures the stellar life cycle from start to finish: the evolution of stars, their formation in different regions of our galaxy, their interactions with other objects and, ultimately, their death.

The team's work was published Oct. 28 in the journal Publications of the Astronomical Society of Australia.

For more sublime space images, check out our Space Photo of the Week archives.

For the first time, scientists have spotted multiple complex building blocks of life in the ice around a star outside the Milky Way.

Using the James Webb Space Telescope (JWST), researchers detected five large, carbon-based compounds around a protostar in the Large Magellanic Cloud, a small galaxy that orbits closely to the Milky Way. The findings could help scientists learn how complex molecules formed in the early universe, according to a study published Oct. 20 in the Astrophysical Journal Letters.

The Large Magellanic Cloud is a dwarf galaxy 160,000 light-years from Earth in the Local Group, a collection of gravitationally bound galaxies that includes the Milky Way. The Large Magellanic Cloud is filled with hot, luminous stars that flood it with ultraviolet radiation. It also has fewer elements heavier than helium than the Milky Way does. These conditions make it similar to those expected in galaxies in the early universe.

"What we learn in the Large Magellanic Cloud, we can apply to understanding these more distant galaxies from when the universe was much younger," study co-author Marta Sewilo, an astronomer at the University of Maryland and NASA's Goddard Space Flight Center, said in a statement. "The harsh conditions tell us more about how complex organic chemistry can occur in these primitive environments where much fewer heavy elements like carbon, nitrogen and oxygen are available for chemical reactions."

In March 2024, the researchers pointed the JWST at a developing star, dubbed ST6, in the Large Magellanic Cloud. Using instruments that measure infrared light, they discovered five complex carbon-based molecules in the ice around the star: methanol, acetaldehyde, ethanol, methyl formate and acetic acid.

Of the five molecules, only methanol has been previously detected in protostars outside the Milky Way. Acetic acid, the main component in vinegar, had never even been conclusively found in space ice before.

"Before Webb, methanol had been the only complex organic molecule conclusively detected in ice around protostars, even in our own galaxy," Sewilo said. "The exceptional quality of our new observations helped us gather an immense amount of information from a single spectrum, more than we've ever had before."

The researchers also found signals that might be caused by a chemical called glycolaldehyde, although further study will be needed to confirm its presence. Glycolaldehyde can react with other molecules to form a type of sugar called ribose, an important component of ribonucleic acid (RNA), which is essential for life.

Finding such complex molecules in the Large Magellanic Cloud suggests that chemical reactions on the surfaces of dust grains can produce complex molecules even under harsh conditions, the researchers said. In future studies, the team plans to look for these and similar molecules around other protostars, both in the Milky Way and in nearby galaxies.

"With this discovery, we've made significant advancements in understanding how complex chemistry emerges in the universe and opening new possibilities for research into how life came to be," Sewilo said in the statement.

Using the James Webb Space Telescope (JWST), astronomers have spotted a very bright and mysterious object that could be a galaxy that emerged just 100 million years after the Big Bang, which would make it the universe's earliest known galaxy, a new study suggests.

Alternatively, Capotauro may be an extraordinary brown dwarf (a "failed star" that is more massive than the largest gas giant planets but not large enough to sustain nuclear fusion in its core) that lives on the outer edges of the Milky Way while smoldering at a mere 80 degrees Fahrenheit (27 degrees Celsius).

Capotauro's exact identity is not certain yet, the researchers wrote in the paper, which was posted Sept. 1 to the preprint server arXiv but has not been peer-reviewed yet.

"Capotauro, whatever it is, seems really interesting and promising," co-author Giovanni Gandolfi, an astrophysicist at the National Institute of Astrophysics in Italy, told Live Science.

Capotauro was originally spotted by Gandolfi and his team during a previous study, in which they tried to identify very old galaxies in JWST observations. But the lack of fine-grained data made it impossible to narrow down the object's identity, which Gandolfi said was like having a slither of DNA at a crime scene but too many matches in the FBI database to be helpful.

Then, in March, JWST released more data on Capotauro that was like getting a partial fingerprint, thus allowing them to whittle down the list to just a handful of suspects, Gandolfi said.

To determine what Capotauro could be, the team used images taken by JWST's Near Infrared Camera (NIRCam) at seven wavelengths as part of the Cosmic Evolution Early Release Science (CEERS) survey to measure Capotauro's brightness. The object was detected only at the two longest NIRCam wavelengths.

Then, they used limited, but more fine-grained data from JWST's Near Infrared Spectrograph (NIRSpec) to get a more accurate picture of Capotauro's age and temperature.

Combining the NIRCam and NIRSpec data, the researchers used models to test three possible galaxy configurations, as well as a scenario in which Capotauro might instead be a brown dwarf on the outer rim of the Milky Way. They also tested a range of other possible scenarios, such as the object being a very odd young galaxy or a peculiar exoplanet.

The results were inconclusive, meaning the team could not decisively determine Capotauro's identity. However, they identified the two most likely options.

Under the early-galaxy interpretation, Capotauro was consistently found to have formed around 100 million years after the Big Bang — pushing the age of the oldest known galaxy back by around 200 million years. It was estimated to be gigantic, at over a billion solar masses.

The other possibility is that Capotauro is a very unusual brown dwarf. If this is the case, Capotauro would be the coldest and farthest known brown dwarf in our galaxy, at over seven light-years away and only 300 kelvins (80 F, or 27 C), the researchers wrote in the study. If Capotauro is a pristine brown dwarf, Gandolfi said, scientists now have the chance to investigate the formation of our galaxy.

Both possibilities are "very exciting" because they would challenge what we thought we knew about our own galaxy and how galaxies form and evolve in general, Gandolfi added.

Muhammad Latif, an astrophysicist at United Arab Emirates University who was not involved in the research, said Capotauro is "one of the most puzzling discoveries" from JWST to date.

"It's a very intriguing object in the sense that whatever the way you interpret it, it basically is kind of pushing the boundaries of our knowledge to the edge," he told Live Science.

More precise data on the light emitted by Capotauro is needed to pinpoint its exact properties, Latif said. The team has submitted a request for JWST to gather more data on this mysterious object, Gandolfi added, and is scanning other areas of the universe for similar-looking objects.

Dark matter near the center of our galaxy is "flattened," not round as previously thought, new simulations reveal. The discovery may point to the origin of a mysterious high-energy glow that has puzzled astronomers for more than a decade, although more research is needed to rule out other theories.

"When the Fermi space telescope pointed to the galactic center, it measured too many gamma rays," Moorits Mihkel Muru, a researcher at the Leibniz Institute for Astrophysics Potsdam in Germany and the University of Tartu in Estonia, told Live Science via email. "Different theories compete to explain what could be producing that excess, but nobody has the definitive answer yet."

Early on, scientists proposed that the glow might come from dark matter particles colliding and annihilating each other. However, the signal's flattened shape didn't match the spherical halos assumed in most dark matter models. That discrepancy led many scientists to favor an alternative explanation involving millisecond pulsars — ancient, fast-spinning neutron stars that emit gamma-rays.

Now, a study published Oct. 16 in the journal Physical Review Letters and led by Muru challenges the long-standing assumption about the shape of dark matter. Using advanced simulations of the Milky Way, Muru and his colleagues found that dark matter near the galactic center is not perfectly round, but flattened — just like the observed gamma-ray signal.

A persistent cosmic puzzle

Gamma-rays are the most energetic form of light. They are often produced in the universe's most extreme environments, such as violent stellar explosions and matter swirling around black holes. Yet even after accounting for known sources, astronomers have consistently found an unexplained glow coming from the Milky Way's core.

One proposed explanation is that the radiation originates from dark matter — the invisible substance that makes up most of the universe's mass. Some models suggest that dark matter particles can occasionally smash together, converting part of their mass into bursts of gamma-rays.

"As there are no direct measurements of dark matter, we don't know a lot about it," Muru said. "One theory is that dark matter particles can interact with each other and annihilate. When two particles collide, they release energy as high-energy radiation."

But this theory fell out of favor when the flattened, disk-like shape of the gamma rays failed to match up with the hypothesized shape of dark matter haloes — which are thought to be spherical.

Rethinking the shape of dark matter

Muru and his colleagues set out to revisit the basic assumption that dark matter in the inner galaxy must be spherical. Using high-resolution computer simulations known as the HESTIA suite, which re-creates Milky Way-like galaxies within a realistic cosmic environment, the team studied how dark matter behaves near the galactic center.

They found that past mergers and gravitational interactions can distort the distribution of dark matter, flattening it into an oval or box-like shape — much like the bulge of stars seen in the middle of our galaxy.

"Our most important result was showing that a reason why the dark matter interpretation was disfavored came from a simple assumption," Muru said. "We found that dark matter near the center is not spherical — it's flattened. This brings us a step closer to revealing what dark matter really is, using clues coming from the heart of our galaxy."

This revised picture means that the pattern of gamma-rays expected from dark matter annihilation could naturally look very similar to what astronomers observe. In other words, the dark matter explanation might have been underestimated simply because scientists were using the wrong shape.

What comes next

Although the new findings strengthen the case for dark matter as the origin of the gamma-ray signal, they don't close the debate. To distinguish between dark matter and pulsars, astronomers need sharper observations.

"A clear indication for the stellar explanation would be the discovery of enough pulsars to account for the gamma-ray glow," Muru said. "New telescopes with higher resolution are already being built, which could help settle this question."

If upcoming instruments, such as the ​​Square Kilometre Array (SKA) and the Cherenkov Telescope Array (CTA), reveal many tiny, point-like sources at the galactic center, it would favor the pulsar explanation. If, instead, the radiation remains smooth and diffuse, the dark matter scenario would gain support.

"A 'smoking gun' for dark matter would be a signal that matches theoretical predictions precisely," Muru noted, adding that such a confirmation will require both improved modeling and better telescopes. "Even before the next generation of observations, our models and predictions are steadily improving. One future outlook is to find other places to test our theories, such as the central regions of nearby dwarf galaxies."

The mystery of the gamma-ray excess has endured for more than 10 years, with each new study adding a piece to the puzzle. Whether the glow comes from dark matter, pulsars or something entirely unexpected, Muru's results highlight how the galaxy's structure itself may hold vital clues. By reshaping our understanding of the Milky Way's dark core, scientists are inching closer to answering one of the most profound questions in modern astrophysics — what dark matter really is.

Astronomers may be closing in on the age and origin of the interstellar comet 3I/ATLAS as it barrels toward the center of our solar system.

A new study that models the last 4 million years of the comet's journey through the Milky Way hints that the interstellar visitor came from far, far away — potentially originating from the wild frontier where the galaxy's oldest and youngest stars meet. If that's the case, the comet may be a relic of the early galaxy, dating billions of years older than Earth's sun.

First spotted in late June and confirmed by NASA in early July, 3I/ATLAS is a peculiar comet whose staggering speed and odd trajectory indicate that it came from a star system beyond our own. It is only the third interstellar object ever detected — after 1I/'Oumuamua and 2I/Borisov — and appears to be the largest so far, with recent estimates putting it somewhere between 3 and 7 miles (4.8 to 11.2 kilometers) wide.

Galactic grand tour

This cosmic visitor is currently taking a months-long sightseeing tour through our inner solar system, completing a close approach to Mars on Friday (Oct. 3) and poised to make its closest swoop past the sun on Oct. 30, according to NASA. After that, it will head out toward interstellar space again, passing Jupiter in March of 2026 before finally disappearing from view. The comet poses no threat to Earth.

While 3I/ATLAS's immediate trajectory is easy to predict, figuring out where it came from is much harder.

Traveling at about 130,000 miles per hour (210,000 kmh), a record for interstellar objects, the renegade ice ball has been picking up speed for millions, if not billions, of years. That leaves it vulnerable to the gravitational tugs of an untold number of Milky Way stars. Just as NASA uses the gravitational influence of our solar system's planets to slingshot spacecraft into deeper orbits, 3I/ATLAS could easily have been knocked off its original trajectory by the gravity of massive stars intervening in its path.

Now, new research published to the preprint server arXiv makes the best effort yet to pin down the comet's origins by looking at which nearby stars, if any, may have influenced its orbit.

Using data from the European Space Agency's now-retired Gaia space telescope, the study authors traced the comet's trajectory back in time 4.27 million years and identified 62 nearby stars that the interstellar object likely encountered along the way. Using Gaia's high-definition data on the stars' motions, velocities and sizes, the study authors concluded that none of them have significantly altered the comet's orbit — hinting that it did not originate anywhere near us.

"We have found that none of the stars in the solar neighborhood can explain the trajectory and high velocity of 3I/ATLAS," lead study author Xabier Pérez-Couto, an astrophysics postgraduate student at Spain's Universidade da Coruña, told Live Science in an email. Only one nearby star, measuring about 70% the mass of the sun, appears to have impacted the comet's trajectory at all, but it was only by a negligible amount, the researchers added in their paper.

This led the team to postulate that "3I/ATLAS is a very old object, that has been traveling for [billions of years], and that its origin belongs to the border of the thin disk," Pérez-Couto said.

Object from the wild frontier?

What's so special about that? Spiral galaxies like the Milky Way divide their stars between a thin disk and a thick disk. Slicing through the central bulge of our galaxy, the younger and smaller thin disk is thought to contain the vast majority of the Milky Way's stars and star-forming gases — most of which are rich in elements heavier than hydrogen and helium, picked up from the older generations of stars that lived and died before them. By contrast the broader thick disk, wrapped around the borders of the thin disk, has long ceased its star formation. It contains a smaller — but much older — sampling of stars that are poor in heavy metals, according to Swinburne University of Technology in Australia.

If comet 3I/ATLAS did indeed originate from the border of these two disks, it could mean the object is incredibly old — potentially 10 billion years old, making it more than double the age of our roughly 4 billion-year-old sun. According to Pérez-Couto, the comet was likely "ejected from the primordial disk of an early formed planetary system," potentially making it a valuable time capsule of the ancient Milky Way.

However, the new study acknowledges the limitations of its approach: by looking at nearby stars, the analysis only accounts for a few million years of the comet's long history, making its exact origin still highly uncertain. As 3I/ATLAS continues to zoom through the solar system, scientific instruments on Earth and Mars, as well as those in orbit around Jupiter, will soon have the chance to study it in much greater detail. Unraveling the interstellar object's composition will provide essential clues to its cosmic birthplace — and potentially open a precious window into our galaxy's past.

A huge "wave" is rippling through our galaxy, pushing billions of stars in its wake, a new study reveals.

The Milky Way's galactic wave was spotted in mapping data from the European Space Agency's (ESA) Gaia space telescope, which charted the positions and movement patterns of millions of stars with high accuracy before retiring earlier this year.

Like ripples in a pond, the wave has a very large influence: It affects stars between 30,000 and 65,000 light-years away from the galaxy's center, ESA officials said in a statement. That's a large percentage of the Milky Way, which is roughly 100,000 light-years across.

Astronomers still don't know what started the motion. It could have been a past collision with a smaller, dwarf galaxy that caused the large shake, ESA officials said, but more investigation is required to answer that question.

The results were published July 14 in the journal Astronomy & Astrophysics.

Mapping the wave

Gaia mapped the speeds and motions of stars for nearly a dozen years. In 2020, the telescope observed that the disk of the Milky Way wobbles like a spinning top. The newfound wave was charted by following the movements and positions of young, giant stars as well as a set of Cepheids — stars that have predictable-but-variable brightness.

"Because young giant stars and Cepheids move with the wave, the scientists think that gas in the disc might also be taking part in this large-scale ripple," ESA officials wrote in the statement. "It is possible that young stars retain the memory of the wave information from the gas itself, from which they were born."

ESA officials likened the galactic wave to "the Wave" done by a crowd at a stadium: In a group movement starting from one side of the stadium and moving section by section to the other side, individuals rise from their seats, fully stand up with their arms extended, and then sit back down.

A similar type of wave motion is visible when our galaxy is observed edge-on. Such vertical motions, represented by arrows, show ripples of movement far across the Milky Way's disk.

"This observed behaviour is consistent with what we would expect from a wave," lead author Eloisa Poggio, an astronomer at the National Institute of Astrophysics in Italy, said in the statement.

The newly discovered wave could also be related to a much smaller Milky Way ripple already known by scientists. Called the Radcliffe Wave, it is visible about 500 light-years from the sun and stretches for 9,000 light-years across space.

"However, the Radcliffe Wave is a much smaller filament, and located in a different portion of the galaxy's disc compared to the wave studied in our work," Poggio said. "The two waves may or may not be related. That's why we would like to do more research."

Black holes are often seen as cosmic monsters that swallow anything unlucky enough to stray too close. But new research suggests they do not always win — some stars can skim the Milky Way's central black hole, Sagittarius A*; lose mass; and stagger away. Scarred but alive, these survivors shine brighter than before, leaving clues that astronomers are only now learning to read.

"Just as the moon pulls tides on Earth, a black hole tugs on a star with far greater force," Rewa Clark Bush, a doctoral candidate in astronomy at Yale University and lead author of the study, told Live Science in an email. Push too far, and the star unravels. Yet some withstand the strain. "One of the stars we modeled lost over 60 percent of its envelope but still retained enough core material that it survived and escaped," Bush said.

The authors think that by counting survivor stars, astronomers might measure how often Sagittarius A* feeds on nearby stars — and the number may help to explain how our galaxy's central black hole grew to 4 million times the mass of the sun.

"Black holes are like chickens in a coop that only eat what they are fed," Heino Falcke, a professor of astrophysics at Radboud University in the Netherlands, not involved in the study, told LiveScience in an email. "The study provides a new toolbox to find these marred stars and learn about the history of our galactic center black hole's feeding habits."

Brighter after the storm

The team used advanced 3D simulations to follow stars brushing past the Milky Way’s black hole and track their long-term evolution. The results, published Aug. 27 in The Astrophysical Journal Letters, showed that a near miss — known as a partial tidal disruption — can trigger a brilliant transformation. A survivor star may throw off ribbons of plasma, swell to many times its original size, and glow up to 10 times brighter for thousands of years.

The show, however, does not last. Surviving stars gradually shrink and begin to masquerade as ordinary stars. Their only giveaway is chemical: The violence dredges up helium and nitrogen from the core to the surface.

"You would need to take spectroscopic data," Bush said — breaking starlight into its component colors — "to notice anomalies that reveal the trauma."

Giuseppe Lodato, an associate professor of astrophysics at the University of Milan, not involved in the study, told Live Science in an email that although survivor stars are well known to astrophysicists, this study stands out for characterizing their brightness and chemical evolution over time.

A clue to the G objects

The study may also address a mystery that has lingered in the Milky Way's core for years. Astronomers have observed several fuzzy light sources known as G objects. These bodies move like stars yet look like diffuse clouds in infrared images. Survivor stars fit the description — they're swollen and wrapped in material blown off during disruption.

"It is very exciting how the authors make a link with the still mysterious and heavily debated G objects," Selma de Mink, scientific director at the Max Planck Institute for Astrophysics in Germany, not involved in the study, told Live Science in an email.

Spotting these stars is not an easy task. Sjoert van Velzen, an assistant professor at the Leiden Observatory in the Netherlands, not involved in the study, told Live Science in an email that even the most ambitious new surveys, such as those undertaken by the Vera C. Rubin Observatory, will reveal thousands of bright flares from complete tidal disruptions in distant galaxies, not the faint remnants that slip away.

"The galactic center is crowded, with stardust blocking most optical light," de Mink said. Infrared instruments such as GRAVITY, which she likened to thermal cameras piercing smoke, are better suited to identifying swollen stars that may hide among the puzzling G objects.

Astronomers are scratching their heads after detecting a bizarre, long-lasting cosmic explosion unlike anything previously observed.

The explosion was a series of repeated outbursts of high-energy radiation, known as a gamma-ray burst. These bursts, the most powerful known explosions in the universe, typically only last for milliseconds to minutes, yet this one was observed erupting for nearly an entire day in July.

Scientists can't explain the record-shattering duration of the event, which occurred outside of the Milky Way and is officially named GRB 250702BDE, according to a study published Aug. 29 in The Astrophysical Journal Letters. Gamma-ray bursts are usually caused by the death of a giant star, but they're typically singular events. This one is unlike any other in 50 years of gamma-ray burst (GRB) observations, according to study co-lead author Antonio Martin-Carrillo, an astrophysicist at University College Dublin.

"GRBs are catastrophic events so they are expected to go off just once because the source that produced them does not survive the dramatic explosion," Martin-Carrillo said in a statement. "This event baffled us not only because it showed repeated powerful activity but also because it seemed to be periodic, which has never [been] seen before."

Related: 'It gave me goosebumps': Most powerful gamma ray burst ever detected hid a secret, scientists say

NASA's Fermi Gamma-ray Space Telescope first recorded the burst on July 2. Researchers then discovered that the Einstein Probe, an X-ray space telescope run by the Chinese Academy of Sciences with European partners, had detected activity from it on July 1, almost a day earlier.

To study the burst in more detail, a team at the European Southern Observatory (ESO) turned to the Very Large Telescope, one of the world's most advanced optical telescopes located in Chile’s Atacama desert. While originally thought to have occurred inside our galaxy, the Very Large Telescope observations suggested the strange signal had come from beyond it, an observation later confirmed by the Hubble Space Telescope, according to the study.

The study authors explored several possible explanations for the unprecedented repeated explosion.

"If a massive star – about 40 times the mass of the Sun – had died, like in typical GRBs, then it had to be a special type of death where some material kept powering the central engine," Martin-Carrillo said.

Another possible explanation is that the radiation blasts were emitted when a star, potentially a white dwarf, was ripped apart by a black hole in what's known as a tidal disruption event (TDE). But in order to produce the continuing explosion, this wouldn't have been any ordinary black hole.

"Unlike more typical TDEs, to explain the properties of this explosion would require an unusual star being destroyed by an even more unusual black hole, likely the long-sought 'intermediate mass black hole,'" Martin-Carrillo said. "Either option would be a first, making this event extremely unique."

Intermediate-mass black holes are larger than the stellar-mass black holes (formed when massive stars collapse in on themselves) but smaller than the supermassive black holes at the center of most galaxies. Astronomers expect that stellar-mass black holes collide and merge over time to form intermediate-mass black holes, but they've proven incredibly difficult to locate.

The team behind the new study is monitoring the aftermath of the explosion and deciphering its cause. The next step will be determining the precise location of the explosion, which will help researchers measure how much energy it generated.

"We are still not sure what produced this or if we can ever really find out but, with this research, we have made a huge step forward towards understanding this extremely unusual and exciting object," Martin-Carrillo said.

Black hole quiz: How supermassive is your knowledge of the universe?

At precisely 2:06 a.m. EDT Saturday (Aug. 23), the moon will enter its new moon phase — something it does every 29.5 days. However, this new moon will have a special title and significance on the calendar. Meet the "black moon."

It's not something that can be seen in the sky, however. A new moon occurs when the moon passes roughly between Earth and the sun, making the surface of the moon invisible from Earth. So why is this particular new moon called a "black moon"?

A black moon is the opposite of a blue moon — and just as rare. As with blue moons, there are two types of black moon. A new moon can get that name if it's the second new moon in a single calendar month. That can happen when there's a new moon on or around the first day or two of a month. It's then guaranteed that a second new moon will occur later that month. This kind — called a monthly black moon — occurs approximately once every 29 months, according to Time and Date. (The next monthly black moon will occur on Aug. 31, 2027.)

However, astronomers also use the term "black moon" to refer to the third new moon in a season of four new moons. That particular calendar quirk is what's happening this weekend — and it's all down to a new moon occurring soon after a solstice or an equinox.

The current season — summer in the Northern Hemisphere and winter in the Southern Hemisphere — began with the solstice on June 20 or 21 (depending on your time zone) and will end with the equinox on Sept. 22. Within that period, there are new moons on June 25 (just four days after the solstice), July 24, Aug. 23 and Sept. 21 (one day before the equinox). It's a tight squeeze, but there's just enough time for four new moons to occur in a single summer.

The third of these new moons (on Aug. 23) is known as a seasonal black moon. This type of new moon occurs once about every 33 months — making it slightly rarer than a monthly black moon.

Related: The 10 best stargazing events of 2025

Although you won't be able to see the black moon with the naked eye, its timing offers a special opportunity for stargazers: a moonless night perfect for enjoying the summer stars just as the Milky Way is looking its best from the Northern Hemisphere.

The best way to get a good look at the arc of our galaxy overhead is to find a location away from light pollution, preferably somewhere with no cities on the southern horizon. Find the three bright stars of the vast Summer Triangle in the southeast — Vega, Deneb and Altair. The Milky Way will be streaming through the left side of the Summer Triangle, roughly from Deneb down to Altair and, from there, down to the southern horizon.

Although the Milky Way is visible in any moonless night sky, the night of the black moon is the perfect opportunity to see it at its best.

Astronomers have discovered a vast cloud of gas and dust stretching out for a staggering 200 light-years and lurking in a poorly explored region of the Milky Way.

The structure, named the Midpoint cloud, is an example of a Giant Molecular Cloud (GMC). It was discovered by the team using the Green Bank Telescope. Peeling back the layers of the Midpoint cloud, they found dynamic regions including several potential sites of new star formation and dense lanes of dust feeding the heart of our galaxy.

"No one had any idea this cloud existed until we looked at this location in the sky and found the dense gas," team leader and National Radio Astronomy Observatory scientist Natalie Butterfield said. "Through measurements of the size, mass, and density, we confirmed this was a giant molecular cloud."

The active region of the GMC and its thick lanes of matter could reveal how material flows from the Milky Way's disk to the very heart of our galaxy.

"These dust lanes are like hidden rivers of gas and dust that are carrying material into the center of our galaxy,” Butterfield continued. "The Midpoint cloud is a place where material from the galaxy’s disk is transitioning into the more extreme environment of the galactic center and provides a unique opportunity to study the initial gas conditions before accumulating in the center of our galaxy."

The gas within the Midpoint cloud exists in a turbulent state, which mirrors conditions found within gas at the Milky Way's center. This chaotic motion could be triggered by material flowing along dust lanes itself or by clashes between the Midpoint cloud and other molecular clouds.

Related: 'Ice cube' clouds discovered at the galaxy's center shouldn't exist — and they hint at a recent black hole explosion

Also within the Midpoint cloud are several clumps of dense gas and dust that could be about to collapse and birth new stars.

One clump, designated Knot E, appears to be a small but dense cloud of gas that is in the process of being eroded by the radiation blasted at it by stars in its proximity. Formations like this are referred to as free-floating evaporating gas globules (frEGGs).

The astronomers also discovered a new source of intense microwave radiation called a "maser" that could be further evidence of intense star formation within the Midpoint cloud.

The researchers didn't just discover evidence of stellar birth with this GMC, however. A shell-like structure in the Midpoint cloud appears to have been caused by the explosive supernova deaths of massive stars.

The research conducted by the team suggests the Midpoint cloud is vital to the flow of matter from the disk of the Milky Way to its heart.

This would feed star formation in the thick central stellar bar that churns around the center of our galaxy. Similar structures of dense stars are found in other barred spiral galaxies.

That means further investigation of this cloud and its surroundings could help develop a clearer picture of how the building blocks of stars gather at the center of galaxies.

"Star formation in galactic bars is a bit of a puzzle," team member and Green Bank Observatory scientist Larry Morgan said. "The strong forces in these regions can actually suppress star formation.

"However, the leading edges of these bars, such as where the Midpoint is located, can accumulate dense gas and trigger new star formation."

The team's research was published on Wednesday (July 16) in The Astrophysical Journal.

Two of the strangest structures in the galaxy just got even stranger.

Ballooning above and below the Milky Way's center like a massive hourglass, the mysterious Fermi bubbles loom large over our galaxy. These enormous twin orbs of superheated plasma have been gushing out of the galactic center for millions of years. Today, they span some 50,000 light-years from tip to tip, collectively making them half as tall as the Milky Way is long.

Now, scientists studying the perplexing bubbles with the U.S. National Science Foundation Green Bank Telescope in West Virginia have discovered something shocking: Nestled deep within the superhot bubbles are gargantuan clouds of cold hydrogen gas that have inexplicably survived in an extreme environment.

According to the researchers, these bewildering clouds are likely the remnants of much larger structures that puffed out of the galaxy's center several million years ago.

"Think of it like dropping an ice cube into boiling water: a small one melts quickly, but a larger one lasts longer — even as it dissolves," lead study author Rongmon Bordoloi, an associate professor in the Department of Physics at North Carolina State University, told Live Science in an email. "We believe these clouds may be remnants of much larger structures that are currently being eroded by the galactic wind."

The discovery could indicate that our galaxy's central black hole experienced a violent outburst of matter more recently than previously thought, Bordoloi added. The research describing the clouds was published July 7 in The Astrophysical Journal Letters.

Baffling bubbles

Towering over the galactic center, the Fermi bubbles were discovered in 2010 by NASA's Fermi Gamma-ray Space Telescope. Despite being comparable to our galaxy in size, the bubbles are visible only in gamma-rays, and they overlap with an equally mysterious X-ray counterpart known as the eROSITA bubbles.

These bubbles are incredibly hot, with the plasma that makes up the Fermi bubbles reaching more than a million kelvins (nearly 2 million degrees Fahrenheit). It's thought that the bubbles are likely the result of an ancient, violent outburst from the Milky Way's central black hole, which spewed twin jets of matter above and below the galactic plane simultaneously, scooping up nearby matter in the process and flinging it outward into space.

Related: Scientists discover rare planet at the edge of the Milky Way, using space-time phenomenon predicted by Einstein

The newly discovered cold hydrogen clouds may be remnants of some of that matter, according to the study authors. Spotted with the Green Bank Telescope, the cold clouds range from about 13 to 91 light-years across, making each one many times larger than our solar system.

However, for those cold clouds to survive in the superhot environment where they were discovered — well within the Fermi bubbles, about 13,000 light-years above the galaxy's center — they must have been significantly larger when they were first swept up into the thrall of the bubbles, Bordoloi said.

"In principle, these clouds shouldn't have survived this long," he added. "Yet they do exist, which gives us a kind of clock: their survival implies that the black hole at the Milky Way's center erupted just a few million years ago. In cosmic terms, that's a blink of an eye."

This discovery could help solve a major mystery about the Fermi bubbles by significantly constraining how old they are. This age, in turn, hints that our galaxy's monster black hole may experience violent, sporadic outbursts whenever large amounts of material fall into it, with the last one occurring more recently than previously thought. However, the precise schedule of black hole eruptions in our galaxy remains an open question.

"What's clear is that features like the Fermi Bubbles — and more recently, the eROSITA Bubbles — suggest the center of the Milky Way has been much more active in the recent past than we once believed," Bordoloi concluded.

The Milky Way may be surrounded by dozens of yet-to-be-detected satellite galaxies, scientists claim.

Using the highest-resolution simulation of our galaxy's dark matter — an invisible entity that shapes the large-scale structure of the universe — and new mathematical models, cosmologists predict that more than 100 additional satellite galaxies beyond the ones already cataloged may be swirling around our own.

If those galaxies are spotted by telescopes, they could offer support for the standard model of cosmology — the dominant model of our universe that explains how galaxies form. The researchers presented their findings July 11 at the Royal Astronomical Society's National Astronomy Meeting in Durham, England.

"We know the Milky Way has some 60 confirmed companion satellite galaxies, but we think there should be dozens more of these faint galaxies orbiting around the Milky Way at close distances," lead researcher Isabel Santos-Santos, a graduate student at Durham University, said in a statement. "One day soon we may be able to see these 'missing' galaxies, which would be hugely exciting and could tell us more about how the Universe came to be as we see it today."

According to the standard theory of cosmology, known as lambda cold dark matter (LCDM), both dwarf galaxies and large ones such as our own take shape within clumps called galactic halos. These vast spheres of stars float like leaves on a pond of dark matter, the mysterious substance believed to make up 85% of the universe's matter.

Dark matter doesn't reflect light, so it hasn't been observed directly. But scientists see evidence for it in the shapes of galaxies, the warping of starlight as it passes through them, and the acceleration of stars to otherwise inexplicable speeds as they orbit galactic centers.

Related: Scientists discover rare planet at the edge of the Milky Way using space-time phenomenon predicted by Einstein

This dark matter halo gives the Milky Way a hefty gravitational pull. The pull is so strong, in fact, that over the course of billions of years, it has captured a number of dwarf galaxies (those containing less than a few billion stars) as satellites.

Despite being predicted as plentiful by LCDM, satellite galaxies are faint and therefore hard to detect; many more should exist than astronomers have been able to observe or even simulate. Taken at face value, their absence is yet another crack of doubt in the standard model of cosmology.

But the scientists behind the new research propose a reason for this lack of supporting evidence, at least within simulations: They're not precise enough to model galaxy evolution, so the simulated halos get disrupted, leading to the loss of their satellite galaxies.

To better simulate the possible hidden galaxies, the astronomers turned to the Aquarius simulation, the highest-resolution reconstruction of a Milky Way dark-matter halo. They used the Aquarius simulation to run the GALFORM model — a code that tracks gas cooling, stars forming and matter clumping to form galaxies similar to our own.

According to the simulation, dwarf galaxies have been orbiting the Milky Way for much of the universe's life. Yet during their repeated passes, their dark matter and stars were gradually snatched away by the Milky Way's enormous galactic halo, causing them to appear extremely faint in the present day.

This means that anywhere from 80 to over 100 more dwarf galaxies might exist around our galaxy's outskirts, according to the researchers. If these galaxies are really there, it may not be long before they're detected; the new Vera Rubin Observatory, which is equipped with the largest digital camera ever constructed, could resolve some of these hidden galaxies.

"If the population of very faint satellites that we are predicting is discovered with new data, it would be a remarkable success of the LCDM theory of galaxy formation," co-researcher Carlos Frenk, a professor of astrophysics at the University of Durham, said in the statement. "It would also provide a clear illustration of the power of physics and mathematics. Using the laws of physics, solved using a large supercomputer, and mathematical modelling we can make precise predictions that astronomers, equipped with new, powerful telescopes, can test."

Astronomers have found what they claim is fresh evidence that Earth and our Milky Way galaxy are suspended inside a gigantic void that's skewing our observations of the cosmos.

The radical proposal, made by analyzing echoes of the Big Bang, suggests that our galaxy may be floating in a 2 billion-light-year region that's 20% less dense than average.

If the results hold up, they could help astronomers find the true age of our universe and offer a solution to one of the stickiest conundrums in cosmology — the discrepancy, known as the Hubble tension, that the distant universe expanded more slowly in the past than the nearby universe does today.

The findings would also prompt a major rewrite of existing cosmological models. The researchers shared their findings July 9 at the Royal Astronomical Society's National Astronomy Meeting in Durham, England.

Hubble trouble

Over the past decade, cosmology has been embroiled in a growing crisis as observations — first made by the Hubble Space Telescope and later by the James Webb Space Telescope — suggested that the universe is expanding at different rates depending on where astronomers look.

Currently, there are two gold-standard methods for figuring out this expansion rate, called the Hubble constant. The first involves poring over tiny fluctuations in the cosmic microwave background, an ancient relic of the universe's first light produced just 380,000 years after the Big Bang. This method enabled astronomers to infer an expansion rate of roughly 67 kilometers per second per megaparsec (km/s/Mpc), which closely matches predictions made by the standard model of cosmology.

Related: 'Our model of cosmology might be broken': New study reveals the universe is expanding too fast for physics to explain

But the second method — measuring closer distances with pulsating stars called Cepheid variables — returned a puzzlingly high value for the Hubble constant of 73.2 km/s/Mpc.

This discrepancy may not seem like much, but it's enough to completely contradict the predictions made by the standard model of cosmology. Astronomers have suggested many major and minor rewrites to this model to explain the tension, including tossing out dark energy and dark matter altogether.

But this anomaly could be specific to our cosmic backyard, the astronomers behind the new research suggest.

"A potential solution to this inconsistency is that our Galaxy is close to the centre of a large, local void," lead author Indranil Banik, an astronomer at the University of Portsmouth in the U.K., said in a statement. "It would cause matter to be pulled by gravity towards the higher density exterior of the void, leading to the void becoming emptier with time."

That would make local expansion inside the void faster than it is in denser, more distant regions of the cosmos, he added.

Filling the void

The notion that our part of the universe could be less dense than others first took shape in the 1990s, when researchers found fewer galaxies in our local universe than they expected compared with the surrounding universe.

Further research backed up these observations, indicating that our galaxy may be in the center of a region known as the local hole or KBC void, named after the initials of the study's astronomers. Nonetheless, some astronomers question whether the apparently underdense space could be filled with objects that don't emit light.

To investigate the evidence further, Banik and his colleagues collected 20 years' of data from observations of nearby baryon acoustic oscillations (BAOs) — pressure waves created during the Big Bang that froze in place and expanded alongside the universe, governing the distribution of galaxies we see today.

"These sound waves traveled for only a short while before becoming frozen in place once the universe cooled enough for neutral atoms to form," Banik explained. "They act as a standard ruler, whose angular size we can use to chart the cosmic expansion history."

According to the researchers' BAO measurements, it's 100 times more likely that we live in a cosmic void than a region of average density.

The next step for Banik and colleagues will be to compare their void model to other models to see which best fits the history of the universe's expansion. They will also need to explore tweaks to the standard model of cosmology, including throwing out the assumption that matter is evenly distributed throughout the universe.

The implications would be vast — not just for our understanding of how the universe behaves but for our own place in it. Modern astronomy has consistently revealed that our personal view of the cosmos is unexceptional. However, if we do live in the middle of a void, we could be more unique in our isolation than first thought.

Astronomers have used a space-time phenomenon first predicted by Albert Einstein to discover a rare planet hiding at the edge of our galaxy.

The exoplanet, dubbed AT2021uey b, is a Jupiter-size gas giant located roughly 3,200 light-years from Earth. Orbiting a small, cool M dwarf star once every 4,170 days, the planet's location is remarkable — it is only the third planet in the entire history of space observation to be discovered so far away from our galaxy's dense center.

Yet perhaps more exceptional than the planet's location is the method used to discover it. The effect, known as microlensing, occurs when the light of a host star is magnified by the warping of space-time due to a planet's gravity. The researchers published their findings May 7 in the journal Astronomy & Astrophysics.

"This kind of work requires a lot of expertise, patience, and, frankly, a bit of luck," study co-author Marius Maskoliūnas, an astronomer at Vilnius University in Lithuania, said in a statement. "You have to wait for a long time for the source star and the lensing object to align and then check an enormous amount of data. Ninety percent of observed stars pulsate for various other reasons, and only a minority of cases show the microlensing effect."

Nearly 6,000 alien worlds beyond our solar system have been discovered since the first exoplanet was detected in 1992. The two most common detection methods, called transmit photometry and radial velocity, detect planets through the dimming of host stars as they pass in front of them, or from the wobble that the planets' gravitational tugs impart upon them.

A rarer method, known as microlensing, is derived from Einstein's theory of general relativity and is produced by massive objects as they warp the fabric of the universe, called space-time. Gravity, Einstein discovered, isn't produced by an unseen force but by space-time curving and distorting in the presence of matter and energy.

Related: James Webb telescope discovers its first planet — a Saturn-size 'shepherd' still glowing red hot from its formation

This curved space, in turn, determines how energy and matter move through it. Even though light travels in a straight line, light traveling through a curved region of space-time also travels in a curve. This means that when a planet passes in front of its host star, its gravity acts as a lens — magnifying the star's light and causing its brightness to spike.

"What fascinates me about this method is that it can detect those invisible bodies," Maskoliūnas said, essentially by measuring the bodies' shadows. "Imagine a bird flying past you. You don't see the bird itself and don't know what color it is — only its shadow. But from it, you can, with some level of probability, determine whether it was a sparrow or a swan and at what distance from us. It's an incredibly intriguing process."

AT2021uey b's cosmic shadow was first spotted in 2021 in data taken by the European Space Agency's Gaia telescope, revealing its presence by a momentary spike in the brightness of its host star.

The astronomers then took detailed follow-up observations using Vilnius's Molėtai Astronomical Observatory, from which they calculated its source as a planet 1.3 times the mass of Jupiter. Its host star burns at about half the temperature of our own, and the gas giant sits four times farther than Earth's distance from the sun.

According to the researchers, the planet's discovery so far from the Milky Way's central bulge, in a region that is comparatively sparse in heavier elements needed to form planets, offers a fresh hint of the unlikely places where planets can be found.

"When the first planet around a sun-like star was discovered, there was a great surprise that this Jupiter-type planet was so close to its star," Edita Stonkutė, another Vilnius University astronomer and leader of the microlensing project that found the planet, said in the statement. "As data accumulated, we learned that many types of planetary systems are completely unlike ours — the solar system. We've had to rethink planetary formation models more than once."

The best time to see the core of our stunning home galaxy, the Milky Way, is fast approaching.

Wherever you are on the planet, if you can get away from light pollution and face south without any artificial lights to spoil the view, one of the most spectacular sights in stargazing is all yours.

Although the Milky Way is visible in May from the Northern Hemisphere, it's only in June that the galactic center comes into view. About 26,000 light-years from the solar system, it's located around the constellations Sagittarius and Scorpius, which are both now visible in the south after dark.

"This is the time of year when the Milky Way is visible as a faint band of hazy light arching across the sky all night," says Preston Dyches at NASA in the June 2025 installment of his monthly vlog, What's Up. "What you're looking at is the bright central core of our home galaxy, seen edge-on from our position within the galaxy's disk."

Finding the Milky Way is easy. Look to the east after dark, and you'll see three bright stars rising — Vega in the constellation Lyra, and Deneb in Cygnus, at the top, and Altair in Aquila below them. This is the vast Summer Triangle, an asterism (shape) in the night sky rather than an official constellation.

As seen from the Northern Hemisphere, the fainter top of the Milky Way pours through the Summer Triangle, specifically from Deneb through Altair. Follow it diagonally across from east to south, and low on the southern horizon will be the Milky Way's bright core.

Related: Two stunning conjunctions will light up the night sky this month. Here's how to see Mars and Mercury 'kiss' the moon

The farther south you are, the more of the bright core you'll see and the darker the sky will be at this time of year. Around the solstice on June 20 to 21, nights in the Northern Hemisphere will be at their shortest, with persistent twilight and no astronomical darkness at latitudes north of about 49 degrees north, according to EarthSky. Closer to the equator is better, and so is anywhere in the Southern Hemisphere, where nights are at their longest during June.

The Milky Way will get brighter and higher in a darker sky in July, August and September. Whenever you see it, try taking a long exposure image, which you can try either with one of the best cameras for astrophotography or with a newer smartphone. A tripod will be required for a good image because the shutter will need to be open for about 10 to 25 seconds.

Scientists have found evidence of a previously-undetected dwarf planet at the edge of the solar system.

The object, dubbed 2017 OF201, follows an extreme, oblong orbit, taking some 25,000 Earth years to circle the sun. The findings, which were confirmed by the International Astronomical Union's Minor Planet Center but have not yet been peer reviewed, were published May 21 on the preprint server arXiv.

2017 OF201 is a roughly spherical body about 435 miles (700 kilometers) in diameter, lurking beyond Neptune's orbit. A team of scientists spotted it while poring through archival data from the Blanco telescope in Chile and the Canada-France-Hawaii telescope based in Hawaii. The researchers tracked the object's motion across 19 sets of images spanning seven years.

At its closest, the dwarf planet orbits at nearly 45 AU, or 45 times the distance from Earth to the sun — a similar distance as its fellow dwarf planet Pluto. Based on the newfound object's trajectory, the scientists estimate its last close pass to the sun was in 1930, the same year Pluto was discovered. It's now twice as far away and rocketing off even further into space. At its farthest point, 2017 OF201 will be a whopping 1,600 AU before starting its journey back inward.

This oblong orbit hints at complex gravitational interactions, both with Neptune and with the pull of the Milky Way's gravity.

"There may have been more than one step in its migration," study co-author Sihao Cheng, an astrophysicist at the Institute for Advanced Study in Princeton, New Jersey, said in a statement. "It's possible that this object was first ejected to the Oort cloud, the most distant region in our solar system, which is home to many comets, and then sent back."

Related: Planet Nine: Is the search for this elusive world nearly over?

Because it's so difficult to spot solar system objects this far away, it's possible 2017 OF201 isn't the only dwarf planet waiting to be discovered.

"2017 OF201 spends only 1% of its orbital time close enough to us to be detectable," Cheng said. "The presence of this single object suggests that there could be another hundred or so other objects with similar orbit and size; they are just too far away to be detectable now."

The newly-discovered object could also challenge theories of Planet 9, a proposed but unobserved large planet orbiting billions of miles beyond Neptune. Some scientists have proposed the influence of Planet 9's gravity to explain the clustered orbits of some trans-Neptunian objects. But 2017 OF201 doesn't fit neatly into this observed pattern, and the researchers suggest that the gravitational pull of Planet 9 — if it exists — would knock 2017 OF201 out of the solar system fairly quickly. Further observations will be needed to better understand these possible interactions, the team wrote in the study.

"Even though advances in telescopes have enabled us to explore distant parts of the universe, there is still a great deal to discover about our own solar system," Cheng said.

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

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

"Starlit Ocean"

Photographer: Xingyang Cai

Location: Big Sur, California

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

"Cosmic Fire"

Photographer: Sergio Montúfar

Location: Acatenango volcano, Guatemala

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

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

"Blossom"

Photographer: Ethan Su

Location: Hehuan Mountain Dark Sky Park, Taiwan

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

"One in a Billion"

Photographer: Don Pettit

Location: Earth orbit

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

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

"Bottle Tree Paradise"

Photographer: Benjamin Barakat

Location: Socotra, Yemen

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

"Lake RT5"

Photographer: Tanay Das

Location: Zanskar, Himalayas

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

"A Sea of Lupines"

Photographer: Max Inwood

Location: Lake Tekapo, New Zealand

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

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

"Spines and Starlight"

Photographer: Burak Esenbey

Location: Karas region, Namibia

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

"Boot Arch Perseids"

Photographer: Mike Abramyan

Location: Alabama Hills, California

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

"Universo de Sal"

Photographer: Alejandra Heis

Location: Jujuy, Argentina

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

The Milky Way has millions of small black holes and one giant supermassive black hole at its center. But does the galaxy have any medium-sized black holes? New research suggests the answer is yes: Perhaps a dozen may inhabit the Milky Way, but they are wandering freely through space and are fiendishly difficult to detect.

For decades, researchers have wondered about the prevalence of intermediate-mass black holes (IMBHs). Certainly, every galaxy is capable of producing an enormous number — roughly a handful every century — of small black holes with masses of up to 100 or so times that of the sun. And it appears that when galaxies like the Milky Way first arrived on the cosmic scene, they already had companion supermassive black holes in their hearts. Our own supermassive black hole, Sagittarius A*, has a mass of 4.5 million suns.

But what about the IMBHs? Theoretically, they should have masses of 10,000 to 100,000 solar masses. Finding IMBHs — or disproving their existence — has enormous implications for our understanding of black hole growth and evolution. But so far, there have been only faint, sketchy hints of IMBHs residing in dwarf galaxies, and no direct evidence that they live in a galaxy like the Milky Way.

In April, a team of researchers at the University of Zurich in Switzerland explored whether our current simulations of the universe could conclusively predict if the Milky Way hosts a population of IMBHs. Their paper has been accepted for publication in the journal Monthly Notices of the Royal Astronomical Society.

Related: Is our universe trapped inside a black hole? This James Webb Space Telescope discovery might blow your mind

Cannibal galaxies

Galaxies do not grow up alone. Instead, they develop through the cannibalization of their neighbors, by incorporating their stars — and any black holes — within their volumes. The Milky Way has consumed over a dozen dwarf galaxies, and probably many more, in its long history. Presumably, some of those dwarf galaxies held IMBHs. But the common assumption was that large black holes tend to slink down the centers of their host galaxies, where they go on to merge with the central supermassive black hole.

Through their models, the researchers saw a different story unfold. They used a simulation of the evolution of a Milky Way-like galaxy and found that it can contain somewhere between five and 18 "wandering" IMBHs, which are not located near the central core but are left to roam within the disk of the galaxy. The exact number of IMBHs depends on whether they are born near the core of a soon-to-be-consumed dwarf galaxy or in its outskirts.

Although the researchers were heartened to find that the Milky Way should host a population of IMBHs, they urged caution in interpreting their results. They could not conclusively state what masses these black holes should have or where they would ultimately reside. So, while the new research strongly hints that IMBHs are out there, we do not yet know where to look.

Why do stargazers get so excited about a new moon? At 10:02 p.m. EDT on Monday, May 26, our natural satellite will slip between Earth and the sun and completely disappear from view. As it does, it will leave the night skies free from moonlight, which serious stargazers view as light pollution.

In the week before the new moon, and for a couple of nights after, the night sky gets as dark as possible. That makes the period from May 20 to May 30 the best time of the month to get outside and look up. Here's what to see from mid-latitudes of the Northern Hemisphere, including the continental U.S., at about 10 p.m. (unless otherwise stated).

1. The Big Dipper and Ursa Major

Most people can find the seven stars of the Big Dipper in the night sky, but did you know it's not a constellation? Known as an asterism — a shape of stars — the Big Dipper forms the rear end (and, unhelpfully, long tail) of Ursa Major, the great bear." May is a great time to trace out the many stars of Ursa Major because it's almost directly overhead in the early evening in the Northern Hemisphere as darkness falls, though the bear is upside down.

The easiest way to begin finding it is to start with the bear's three visible paws, which are each marked by a set of double stars — Alula Borealis and Australis, and Tania Borealis and Australis for the bear's two back paws, and Talitha and Talitha Australis for the one visible front paw. Below the latter, the star Muscida marks the bear's head.

2. Leo, the lion

Look to the south as soon as it gets dark, and you'll see a backward question mark of stars that mark the head and forequarters of Leo, the lion. The dot in that question mark (called "the sickle" by stargazers) is the bright star Regulus, which means "little king," according to EarthSky.

3. A small 'planet parade'

If you only get up early once this month, make it 45 minutes before sunrise on Friday, May 23 when, in the east, a crescent moon will appear close to a very bright Venus, with Saturn close by.

4. Boötes, the herdsman

Return to Ursa Major and trace its tail — the handle of the Big Dipper — in an "arc to Arcturus" to the next bright star in the night sky. The fourth-brightest star in the night sky, Arcturus is the brightest star in the constellation Boötes, the herdsman, a key yet little-known shape of stars in spring. Its nine stars trace out the shape of what looks most like a kite, but skip that and focus on what's easy — four stars that are in the shape of a "Y" or champagne flute.

5. The Hercules Cluster

Hidden in the halo of the Milky Way galaxy are strange groups of ancient stars called globular clusters. Huddled in dense balls and thought to be the remains of ancient galaxies gobbled up by our own, there are about 150 of these in the night sky. Remarkably, they are the oldest visible objects in the universe.

One of the best is M13 in the constellation Hercules, the hero, which is high overhead after dark. You'll need a pair of stargazing binoculars, or better still a good backyard telescope, to glimpse it as a dense fuzzy patch. It contains more than 100,000 stars, according to NASA, and is 25,000 light-years distant on the outskirts of the galaxy.

Update: This article was updated on May 22 to indicate that the best stargazing period has begun

Constellations quiz: Can you name all the animals, objects and mythological figures hiding in the night sky?

Why it's so special: If you need an excuse to visit the Southern Hemisphere, the Hubble Space Telescope has just provided one. This spectacular new image, taken with Hubble's Wide Field Camera 3, showcases the Large Magellanic Cloud (LMC), the biggest satellite galaxy of the Milky Way. It is visible only from the Southern Hemisphere.

This dense star field appears as a big, fuzzy patch in the night sky from anywhere in the Southern Hemisphere. Hubble's new view uses five filters to isolate different wavelengths of light, including ultraviolet and infrared light, which the human eye cannot see.

The result is a starry cloudscape of wispy gas that resembles multicolored cotton candy against a background of orange and blue stars. There's also a zoomable version available online.

Related: 42 jaw-dropping James Webb Space Telescope images

Despite being a dwarf galaxy, the LMC may be pivotal in the Milky Way's future. Within the next 10 billion years, our galaxy is expected to collide with Andromeda — a spiral galaxy 2.5 million light-years away and the nearest major galaxy to the Milky Way. In 2019, scientists predicted that the LMC is also heading toward the Milky Way and could begin to interact with it in 2.4 billion years.

The LMC is one of many dwarf galaxies that orbit the Milky Way, but it's one of only two that are visible to the naked eye. The other is the Small Magellanic Cloud (SMC), which can be seen close to the LMC between October and February from the Southern Hemisphere.

The LMC and the SMC are connected by a bridge of gas called the Magellanic Bridge, indicating that they may have interacted in the past. Both dwarf galaxies have been orbiting the Milky Way for about 1.5 billion years. Recent research indicates that the SMC is being torn apart and may in fact be two galaxies. Both dwarf galaxies are named after Portuguese explorer Ferdinand Magellan.

For more sublime space images, check out our Space Photo of the Week archives.

The bright band of the Milky Way is about to make its first great appearance of the year in the Northern Hemisphere.

There are few more impressive sights than the arc of the Milky Way spanning the night sky, but skywatchers don't always know exactly how, when and where to see it. In fact, one-third of humanity — and 80% of Americans — cannot see it.

The reason is light pollution, with the sky's brightness increasing by between 7% and 10% per year between 2011 and 2023, according to a 2023 study published in the journal Science. As a result, if you want to see the Milky Way, you'll need to be as far away from light pollution as possible. Good options include a Dark Sky Place or somewhere that looks dark on a light pollution map.

Although the Milky Way can be seen in some form for about eight months of the year, the galaxy's bright core becomes easier to see — and gets higher in the sky — as of May as seen from midlatitudes of the Northern Hemisphere, which includes the entire continental United States and the most populated parts of Canada.

Related: The 10 best stargazing events of 2025

According to the Milky Way photography website Capture The Atlas, "Milky Way season" runs from February to October, usually between midnight and 5 a.m. local time, though your location and the phase of the moon matter a lot. During May, the period between the last quarter moon on May 20 and the new moon on May 30 is the time to look for the Milky Way.

Even if you have a clear, moonless night, the viewing window is further restricted by when the galaxy's bright core rises from your location. The key is to find out when the Summer Triangle — a shape formed by three bright stars — becomes visible. This vast asterism of Deneb in the constellation Cygnus, Vega in Lyra and Altair in Aquila sits across the Milky Way. If it's above the horizon, you have a good chance of spotting it. Between May 20 and May 30, the Summer Triangle will be up in the east at midnight and higher in the southeast by 3 a.m. local time.

The Milky Way will rise higher into the sky — and appear earlier — as the Summer Triangle becomes more prominent in June and July, but a lack of darkness at mid-northern latitudes around the solstice on June 20-21 makes May the best time to grab a first glance before the Milky Way gets much brighter and higher in the sky in August and September.

Why it's so special: What if a galaxy had only one spiral arm?

Our solar system resides on the outskirts of one of the Milky Way galaxy's estimated four spiral arms, according to Space.com, but not all galaxies are like that. In the latest image from NASA's Hubble Space Telescope, a strange galaxy called NGC 1961 comes into focus that has just one — a single broad, star-speckled spiral arm that appears to stretch toward us as the galaxy is viewed from a skewed angle.

It may seem a dramatic point of view, but it's merely what Hubble sees from its line of sight on its orbital path around Earth. On the far side of the newly imaged galaxy, beyond swirls of stars and dust around a bright center, there is no similarly impressive spiral arm, with just a few wisps of gas and stars instead. The image is also available as a panoramic video, a zoomable version, and as a 15-megapixel download.

Its sole spiral arm long ago earned NGC 1961 the additional name Arp 184 and a place in the Atlas of Peculiar Galaxies, a catalog of galaxies that are neither perfectly symmetrical spiral galaxies nor smooth, spherical elliptical galaxies. First published in 1966 by American astronomer Halton Arp, the atlas collects 338 galaxies that are oddly shaped, many because they're interacting with other galaxies. Others in the atlas are dwarf galaxies in flux.

Related: James Webb telescope's observations of 'impossible' galaxies at the dawn of time may finally have an explanation

There's another reason why Hubble targeted Arp 184/NGC 1961. It's hosted four known supernovas — the powerful explosion of a dying star — in the past four decades (in 1998, 2001, 2013 and 2021). It's exceptionally rare to catch a supernova in the act, so galaxies with a proven track record like this one make prime targets.Arp 184/NGC 1961 was discovered by German-British astronomer William Herschel in 1788, seven years after he discovered the planet Uranus, the first planet to be found in modern times.

According to observations from NASA's Spitzer Space Telescope, the Milky Way has two main spiral arms — the Perseus and Scutum-Centaurus arms — and two less obvious arms, the Sagittarius and Norma arms. Two minor spiral arms are close to the galaxy's center, the Far-3 kiloparsec arm and the Near-3 kiloparsec arm. Our solar system exists in the Orion Spur between the Sagittarius and Perseus arms.

For more sublime space images, check out our Space Photo of the Week archives.

How do you distinguish a galaxy from a mere cluster of stars? That's easy, right? A galaxy is a large collection of millions or billions of stars, while a star cluster only has a thousand or so. Well, that kind of thinking won't get you a Ph.D. in astronomy! Seriously, though, the line between galaxy and star cluster isn't always clear. Case in point, UMa3/U1.

It's easy to distinguish galaxies such as Andromeda and the Milky Way. They are large, gravitationally bound, and dominated by dark matter. It's also easy to distinguish star clusters such as the Pleiades. They are loosely bound star groupings without dark matter. But for a type of small dwarf galaxy known as Ultra-Faint Dwarfs (UFDs) the dividing line gets fuzzy.

UFDs are dominated by dark matter. The mass of the Milky Way, for example, is about 85% dark matter. An ultrafaint dwarf galaxy, however, can have a thousand times more dark matter than luminous matter. This is why they are so faint. Since UFDs often contain some of the oldest stars in the Universe, astronomers love to study them for clues on the origins of galaxies. Which brings us to UMa3/U1.

Related: Scientists discover smallest galaxy ever seen: 'It's like having a perfectly functional human being that's the size of a grain of rice'

Even its name tells us that there is a problem. If, in fact, the object is a dwarf galaxy then its name should be Ursa Major III, as it is a satellite galaxy in the constellation Ursa Major. If it is an ancient star cluster, then it should be named UNIONS 1, since it was discovered by the Ultraviolet Near Infrared Optical Northern Survey (UNIONS). If it is a galaxy, then it is the smallest and most dark-matter dominated galaxy yet discovered. If it is a star cluster, then with an age of about 11 billion years, it is the oldest star cluster yet discovered.

UMa3/U1 is downright tiny. It is only 20 light-years across, contains only about 60 stars, and has a visible mass of just 16 Suns. In comparison, the Pleiades has about the same diameter, but contains more than 1,000 stars and 800 solar masses. So the real question for UMa3/U1 is whether it is dominated by dark matter.

In a recent study, the team looked at several tests to distinguish star clusters and dwarf galaxies. Their first approach was to look at the dynamics of the visible stars, assuming it is a star cluster. Based on their known motions, the team simulated how long it would take for the stars to break free, a process known as evaporation. Based on their simulations, the cluster could survive for another 2-3 billion years. That's a good fraction of the estimated 11 billion year age, which suggests U1 is simply a stable star cluster.

The second test the team applies is what is known as the mass function. This is a plot of the way the mass of the cluster varies with distance. If it is a cluster, then the mass should be more evenly distributed, but if it is a galaxy, stars should be clustered toward the center. Here the data is less conclusive. The distribution of visible stars is a decent match to the cluster model, but for a galaxy the central stars would be mostly white dwarfs and neutron stars, which are too dim to distinguish with current observations.

Overall, the evidence leans towards UMa3/U1 being a star cluster, but the team notes that it will take more observations of other UFDs to be conclusive. Fortunately, upcoming telescopes such as the Vera Rubin Observatory will discover many more faint dwarfs in time.

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

Starry paintings found on ancient Egyptian coffins and tombs indicate that the sky goddess Nut was closely associated with the Milky Way galaxy, according to a new study by an astronomer.

While Egyptologists have long believed Nut was connected with the Milky Way, this new study helps support the idea.

Or Graur, an associate professor of astrophysics at the University of Portsmouth in the U.K., examined 125 depictions of the goddess Nut (pronounced "Noot") on coffins and tomb walls that are up to 5,000 years old. A few of these paintings were unusual in their detail, Graur reported in a study published April 30 in the Journal of Astronomical History and Heritage.

In many depictions of Nut, the goddess is shown naked and arched over the sky, sometimes with stars and solar disks over her body. This posture shows her connection with the sky and her protection of Earth below, according to a statement from the University of Portsmouth. But the unusual paintings showed another aspect of her identity.

For instance, on the outermost coffin of a chantress (a person who performs religious prayers) named Nesitaudjatakhet, there is a depiction of Nut lying down. Her body is covered in stars, and there is "a thick, undulating black curve that bisects Nut's star-studded body and recalls the Great Rift that cleaves the Milky Way in two," Graur wrote in the study.

"I think that the undulating curve represents the Milky Way and could be a representation of the Great Rift — the dark band of dust that cuts through the Milky Way's bright band of diffused light," Graur said in the statement.

Related: 'Everything we found shattered our expectations': Archaeologists discover 1st astronomical observatory from ancient Egypt

Graur noted that similar undulating waves appear along with images of Nut in the decorations of four tombs in the Valley of the Kings. For instance, the ceiling of Ramesses VI (who ruled circa 1143 to 1136 B.C.) has two back-to-back images of Nut that are "separated by thick, golden undulating curves that issue from the base of Nut's head and travel above her back all the way to her rear," Graur said.

The fact that some paintings depict Nut with these undulating waves suggests a close association with the Milky Way, Graur said. The ancient Egyptians may have believed that this association helped her protect the Earth, Graur wrote. Geb, an Egyptian god who represents the Earth, is sometimes seen underneath the arched Nut, he wrote in the study.

Nut was also associated with all other aspects of the day and night sky. "We should not think of the Milky Way as a representation of Nut," Graur wrote in the study. "Instead, we should think of the Milky Way as one more astronomical phenomenon that, like the stars and the Sun, are part of the sky and hence a part of Nut."

The finding is not new to Egyptologists, but it's important to have the same interpretation from an astronomer's point of view, said Rogério Sousa, a professor of Egyptology and ancient history at the University of Lisbon in Portugal.

"I can say that I agree with the identification between Nut and the Milky Way proposed by Or, which has always been implied by Egyptologists," Sousa told Live Science in an email. "But Or being an astronomer [gives it an] astronomical input."

Ancient Egypt quiz: Test your smarts about pyramids, hieroglyphs and King Tut

Astronomers have spotted an immensely powerful "zombie star" shooting through the Milky Way at more than 110,000 mph (177,000 km/h). The stellar cannonball, which has a magnetic field capable of ripping humans apart atom by atom, also has a puzzling origin story that could alter our understanding of similar stellar remnants.

The surprising object, dubbed SGR 0501+4516, is a magnetar, a neutron star with a powerful magnetic field. Neutron stars are the remains of dead stars that have collapsed into shriveled husks the size of small planets while retaining as much mass as sunlike stars. This makes neutron stars the densest known cosmic objects, behind the hypothesized singularities of black holes.

The incredibly compact object, which is one of only 30 known magnetars in the Milky Way, was first discovered in 2008, when it was around 15,000 light-years from Earth. But in a new study, published April 15 in the journal Astronomy & Astrophysics, researchers analyzed data of subsequent sightings of SGR 0501+4516 from the Hubble Space Telescope and the European Space Agency's Gaia spacecraft and found that the stellar remnant is moving through our galaxy much faster than expected.

Magnetars are among the most magnetic objects in the universe, and SGR 0501+4516 is no exception. Experts think the object's magnetic field is around 100 trillion times more powerful than Earth's protective shield.

If SGR 0501+4516 "flew by Earth at half the Moon's distance, its intense [magnetic] field would wipe out every credit card on our planet," NASA representatives wrote in a statement. "If a human got within 600 miles, the magnetar would become a proverbial sci-fi death-ray, ripping apart every atom inside the body." However, the undead star is not expected to get anywhere near the solar system.

Related: Immensely powerful 'magnetar' is emitting wobbly radio signals in our galaxy — and scientists can't explain them

The discovery challenges what we know about how magnetars form. Until now, researchers assumed that these objects are born from the explosions of dying stars that get blown apart before they are reforged into neutron stars. This is what researchers assumed had happened to SGR 0501+4516, which was originally spotted close to the supernova remnant HB9. However, the new study showed that the magnetar is moving too fast and in the wrong direction to have originated from this particular cosmic crime scene.

"Tracing the magnetar's trajectory thousands of years into the past showed that there were no other supernova remnants or massive star clusters with which it could be associated," NASA representatives added.

Uncertain origins

The researchers are still unsure exactly how SGR 0501+4516 was created. But they predict that it formed through the direct collapse of a white dwarf — the leftover core of a star after it has exhausted its fuel — rather than via a stellar explosion.

"Normally, the [supernova] scenario leads to the ignition of nuclear reactions, and the white dwarf exploding, leaving nothing behind," study co-author Andrew Levan, an astronomer at Radboud University in the Netherlands and the University of Warwick in England, said in the statement. "But it has been theorized that under certain conditions, the white dwarf can instead collapse into a neutron star. We think this might be how [this magnetar] was born."

This formation method also hints at the mysterious origin of some fast radio bursts — extremely brief and intense flashes of radio-wave radiation — detected coming from faraway galaxies that are too ancient to host exploding stars, the researchers wrote. However, more data is needed to tell for sure.

"Magnetar birth rates and formation scenarios are among the most pressing questions in high-energy astrophysics, with implications for many of the universe's most powerful transient events," study co-author Nanda Rea, an astrophysicist at the Institute of Space Sciences in Barcelona, Spain, said in the statement.

In 2020, astronomers observed for the first time what appeared to be a star engulfing one of its orbiting planets. But now, new evidence shows something else actually happened.

A planet certainly met its demise at the behest of its star, but now the way it happened looks much different. Rather than this star expanding, it drew the planet closer and closer until it was consumed, new evidence from NASA's James Webb Space Telescope (JWST) reveals. This novel event serves as an equally fascinating first — even if it's not what astronomers initially believed it to be. The researchers published their findings April 10 in The Astrophysical Journal.

"It's not every day that we find these kinds of events," the study's first author, Ryan Lau, an assistant astronomer at the National Science Foundation National Optical-Infrared Astronomy Research Laboratory in Tucson, Arizona, told Live Science. This is "likely the first planetary engulfment event that was caught in the act."

The celestial event, dubbed ZTF SLRN-2020, involves a star and its Jupiter-size planet, located in the Milky Way approximately 12,000 light-years from Earth. While watching the star, researchers noticed a bright flash of optical light, indicating that something — most likely a large planet — had been engulfed by the star, leaving only a cloud of dust behind.

'A very different scenario'

Initially, researchers thought the star was similar to the sun and was following the natural life cycle of sunlike stars. A 2023 paper published in the journal Nature described the star as entering its final stage of life as a red giant, in which it balloons significantly as it exhausts its supply of hydrogen fuel. The sun will meet this fate in about 5 billion years, ultimately swallowing Mercury, Venus and, likely, Earth in the process.

But the data from JWST "paints a very different scenario," Lau said. As JWST's Mid-Infrared Instrument and Near-Infrared Spectrograph gathered information from the scene of the crime, a new picture appeared. The observations revealed that the star had not been emitting light in the form of infrared wavelengths expected from the transition into a red giant. In other words, it wasn't as bright as expected, indicating that the red giant process likely wasn't afoot.

Related: After 2 years in space, the James Webb telescope has broken cosmology. Can it be fixed?

As for the devoured planet, the team proposes that it orbited unusually close to its host star — even closer than Mercury orbits the sun. Ultimately, the Jupiter-size planet started moving closer and closer to its star in a process called orbital decay. Lau and his team attribute this orbital decay to tidal interactions, a phenomenon in which strong gravitational forces between two celestial bodies can change the dynamics between those bodies.

The whole process probably took just a few months, Lau said. After the planet spiraled in toward the star, it made contact with the star's surface. From there, drag forces sucked it into the star's core, where it was fully engulfed. The star then ejected the planetary material, which created the brightening event first detected in 2020. This ejection also included longer-lasting infrared wavelengths and dust, which led astronomers to believe that the star had expanded, when, in fact, it did not.

Events like these can be hard to spot because the light signatures they produce are often quite faint. With the opening of the Vera C. Rubin Observatory, Lau said, these observational signatures — and their associated events — could become much easier to detect.

"We should be finding way more of these," Lau said. "That's one thing I'm very excited about."

Astronomers have uncovered shocking evidence that one of the closest galaxies to our own is being torn to shreds by its neighbor.

Located around 200,000 light-years from Earth, the Small Magellanic Cloud (SMC) is a dwarf galaxy that, alongside its neighbor the Large Magellanic Cloud (LMC), is gravitationally bound to our Milky Way. The two satellite galaxies orbit alongside ours and, in a few billion years, will collide and merge with the Milky Way.

But before that far-future date, a new analysis of star patterns has revealed that a different fate may be in store for the SMC: being torn apart by its larger neighbor. This dire prediction was published April 10 in The Astrophysical Journal Supplement Series.

"When we first got this result, we suspected that there might be an error in our method of analysis," co-author Kengo Tachihara, an astronomer at Nagoya University in Japan, said in a statement. "However, upon closer examination, the results are indisputable, and we were surprised."

Alongside our Milky Way and the LMC, the SMC is part of the Local Group, a collection of roughly 30 galaxies in our cosmic backyard. The SMC’s triangle-shaped patch of a few hundred million stars is relatively small, measuring just 7,000 light-years across compared to our own galaxy's 100,000 light-year diameter, and circles the LMC once every 900 million years and the Milky Way about once every 1.5 billion years.

Related: One of the closest galaxies to the Milky Way is hiding a second galaxy behind it, new research reveals

Yet despite the SMC’s proximity to us, the galaxy's relatively small size and the obscuring effects of interstellar gas and dust have made observing it tricky.

To peer into the SMC’s inner workings, the researchers turned to the European Space Agency's recently retired Gaia spacecraft, which mapped the positions of roughly 2 billion stars within the Milky Way and its surrounding galaxies. By poring through Gaia's third data release, the astronomers tracked the movements of roughly 7,000 stars from within the SMC to arrive at a shocking finding.

"The stars in the SMC were moving in opposite directions on either side of the galaxy, as though they are being pulled apart," Tachihara said. "Some of these stars are approaching the LMC, while others are moving away from it.”

This unexpected movement suggests that the LMC is tugging on its smaller companion, Tachihara said, "leading to its gradual destruction."

The researchers' analysis also revealed that, unlike in our Milky Way, the massive stars tracked within the SMC were not rotating around the galaxy's axis. This suggests that something may be wrong with our understanding of the galaxy's mass and its history of interactions with the LMC and the Milky Way.

Further study of these conundrums could reveal some key insights. The SMC's low metallicity and weak gravitational potential energy means it resembles what many galaxies may have looked like during their infancy in the early universe. This means that studying the interactions between the SMC and the LMC could help astronomers understand how galaxies were sculpted over time.

"We are unable to get a 'bird's-eye view' of the galaxy in which we live – as a result, the SMC and the LMC are the only galaxies in which we can observe the details of stellar motion,” Tachihara noted. “This research is important because it allows us to study the process of star formation in connection with the motion of stars throughout the galaxy."

What it is: Sagittarius C (Sgr C) region of the Milky Way.

Where it is: 25,000 light-years from the solar system in the constellation Sagittarius.

When it was shared: April 2, 2025

Why it's so special: The Milky Way often appears as a reddish, pinkish and bluish-white arc across the night sky, but this new super-long exposure image from South Africa's ground-based MeerKAT radio telescope shows our home galaxy in a completely new way.

Colored in blue, cyan, yellow and white, the main image — whose many bubbles of color are remnants of supernovas — span 1,000 light-years of the Milky Way.

The new radio image helps to put in context the inset infrared image by the James Webb Space Telescope from 2023 of Sagittarius C (Sgr C). This is a 44 light-year-wide region about 200 light-years from the Milky Way's central supermassive black hole, Sagittarius A*, where stars are being formed.

JWST's image revealed more than 500,000 stars, but in this Central Molecular Zone — an extreme environment — stars are not being formed as quickly as astronomers expect. One reason may be the strong magnetic fields around that supermassive black hole, which are shaping the filaments seen by MeerKAT and JWST. These magnetic fields may also be strong enough to resist the gravity that causes dense clouds of gas and dust to collapse to create stars, thus suppressing star formation in Sgr C.

"A big question in the Central Molecular Zone of our galaxy has been, if there is so much dense gas and cosmic dust here, and we know that stars form in such clouds, why are so few stars born here?" said John Bally, an astrophysicist at the University of Colorado Boulder and one of the principal investigators of a related paper published April 2 in The Astrophysical Journal. "Now, for the first time, we are seeing directly that strong magnetic fields may play an important role in suppressing star formation, even at small scales," Bally said in a NASA statement.

MeerKAT is a radio telescope made up of 64 dishes in South Africa's Karoo region. It will eventually form part of a far larger radio telescope called the Square Kilometre Array, the world's largest and most sensitive radio telescope that will also use more than 130,000 Christmas tree-shaped antennas on the traditional lands of the Wajarri Yamaji, in Murchison, Western Australia.

For more sublime space images, check out our Space Photo of the Week archives.

On March 27, scientists bid farewell to the Gaia telescope, bringing to a close its groundbreaking 11-year mission of mapping the Milky Way and our cosmic neighborhood.

Though not as famous as some of its peers like the Hubble or James Webb space telescopes, Gaia has reshaped our understanding of our home galaxy, the Milky Way. Since 2014, the European Space Agency's (ESA) telescope has meticulously charted the cosmos, creating a vast catalog of nearly 2 billion stars, more than 4 million potential galaxies and around 150,000 asteroids, with moons possibly circling hundreds of them.

These observations have led to more than 13,000 scientific studies, with many more likely to follow in the coming years.

"Gaia's extensive data releases are a unique treasure trove for astrophysical research, and influence almost all disciplines in astronomy," Johannes Sahlmann, a physicist at the European Space Astronomy Centre in Spain and a project scientist for the Gaia mission, said in a statement.

After 11 years of operations — nearly double its expected lifetime — Gaia ran out of fuel, prompting its operators at ESA to power down and retire the spacecraft.

The best map of the Milky Way galaxy

Since it launched in December 2013, Gaia charted the cosmos from a vantage point about a million miles (1.6 million kilometers) from Earth, at a spot called Lagrange point 2 (L2), where the gravitational forces of Earth and the sun, and the orbital motion of a satellite balance each other.

Gaia's primary goal was to map the positions and movements of over a billion stars within the Milky Way, creating the largest, most precise 3D map of our galaxy. To do so, it was equipped with twin telescopes pointed in different directions to measure the distances between stars, while three onboard instruments collected data on the positions, velocities, colors as well as chemical compositions of celestial objects.

The exquisite map of our galaxy it assembled has enabled scientists to better understand the galaxy's spiral structure, estimate the shape and mass of the dark matter halo that surrounds the Milky Way, and solve the decades-old mystery of our galaxy's warped and wobbling disk — which is likely due to an ongoing collision with the smaller Sagittarius galaxy.

Additionally, the catalog has provided astronomers with new insights into the ancient nature of parts of our galaxy, suggesting that stars began forming in the Milky Way's disk less than 1 billion years after the Big Bang — far earlier than the previously accepted timeline of 3 billion years.

The telescope's observations have also led astronomers to discover previously hidden stellar streams. For example, in 2020, its database of stars revealed the presence and shape of the largest structure ever observed in our galaxy: a vast ensemble of interconnected stellar nurseries spanning 9,000 light-years, known as the Radcliffe Wave, which may have had a lasting impact on Earth's climate.

"Gaia has changed our impression of the Milky Way," Stefan Payne-Wardenaar, a scientific visualiser at the Heidelberg University in Germany, said in a previous statement.

The spacecraft has serendipitously captured thousands of starquakes — tiny motions on surfaces of stars that cause them to swell and shrink periodically — providing unique insights into the inner workings of stars, and spotted high-velocity stars both escaping our galaxy and, surprisingly, racing toward it. It also uncovered several cosmic "sleeping giants," or black holes — one of which is lurking extremely close to Earth.

Gaia's star catalog has also been used to clock the expansion rate of the universe, fueling the ongoing debate over why the expansion seems to be occurring faster than astronomers expected.

"It is impressive that these discoveries are based only on the first few years of Gaia data, and many were made in the last year alone," Anthony Brown, an associate professor of astronomy at the University of Leiden in Netherlands, said in the statement.

Saying goodbye to the 'discovery machine of the decade'

On March 27, ESA commanded Gaia to use its thrusters for the final time, pushing the spacecraft into a "retirement orbit" safely away from Earth and the scientifically important L2 orbit, which is also home to the James Webb Space Telescope, Euclid telescope and China's Chang'e 6 orbiter.

Last week the mission team deactivated the spacecraft's instruments, which were designed with multiple redundant systems to ensure it could reboot and resume operations after any failure. To prevent its computers from powering back on in the future, operators deliberately corrupted its onboard software, according to the ESA statement.

"We had to design a decommissioning strategy that involved systematically picking apart and disabling the layers of redundancy that have safeguarded Gaia for so long," Tiago Nogueira, Gaia spacecraft operator, said in the statement. "We don't want it to reactivate in the future and begin transmitting again if its solar panels find sunlight."

Team members wrote the names of all 1,500 contributors to the Gaia mission into the spacecraft's onboard memory, as well as personal farewell messages and poems.

The telescope may have gone dark, but scientists hope its discoveries will continue to shine brightly. So far, only a third of the mission's data has been analyzed, as processing the vast amount of information — Gaia is expected to have gathered more than 1 petabyte (1 million gigabytes) of data by the end of its mission — takes months. The next batch of science data is set to be released in 2026, covering a little over five years of observations, with the fifth and final release scheduled for 2030, which will encompass the full 10 years of data.

"Gaia has been the discovery machine of the decade, a trend that is set to continue," Brown said in the statement.

"Space tornadoes" are swirling near the supermassive black hole at the heart of our Milky Way galaxy, new telescope observations have revealed in unprecedented detail.

Astronomers recently zoomed in on the cosmic twisters using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. Although these rotating structures had been seen previously, the new observations with ALMA are 100 times sharper than the earlier views, the team reported in a new paper published in the journal Astronomy & Astrophysics.

The researchers began by pointing ALMA at a region of the galaxy known as the central molecular zone (CMZ), which surrounds our galaxy's core supermassive black hole and is filled with seething clouds of dust and gas. The team wanted to uncover the mechanism driving the relentless motion of these clouds.

Related: High-school student accidentally discovers black hole 'light echo' twice as wide as the Milky Way

They used ALMA to trace certain molecular compounds — such as silicon monoxide, which is particularly good at revealing shock waves — within the maelstrom. This allowed the team to detect previously unseen details in the cosmic dust storms — including a new type of long, slender filament that seems to form when shock waves ripple past.

"Unlike any objects we know, these filaments really surprised us," because they appear to move quickly and in a direction counter to the structures surrounding them, Kai Yang, an astronomer at Shanghai Jiao Tong University and lead author of the study, said in a statement.

The researchers describe these filaments as space tornadoes. "They are violent streams of gas, they dissipate quickly, and they distribute materials into the environment efficiently," the authors said in the statement. The team's observations suggest that, in addition to emitting silicon oxide, these whirlwinds might disperse complex organic molecules — such as methanol, methyl cyanide and cyanoacetylene — throughout the CMZ and beyond.

"ALMA's high angular resolution and extraordinary sensitivity were essential to detect these molecular line emission associated with the slim filaments, and to confirm that there is no associations between these structures with dust emissions," Yichen Zhang, an astrophysicist at Shanghai Jiao Tong University and a co-author of the paper, said in a statement.

Further observations with ALMA will help the researchers determine how widespread these slim filaments are within the CMZ and how they contribute to molecular cycling in the region.

Like a ship sailing through changing weather at sea, our solar system's journey around the center of the Milky Way takes it through varying galactic environments — and one of them may have had a lasting impact on Earth's climate, a new study suggests.

Observations from the European Space Agency's recently retired Gaia mission indicate that around 14 million years ago, our solar system passed through a dense, star-forming region in the direction of the constellation Orion. This region is part of a vast network of star clusters that spans nearly 9,000 light-years and is sculpted into a structure that astronomers have dubbed the Radcliffe Wave in honor of the Harvard Radcliffe Institute in Massachusetts, where the wave’s existence was confirmed.

When our solar system swirled through this structure millions of years ago, it may have received an increased flow of interstellar dust. The timing of this event aligns with Earth's transition from a warmer to a cooler climate, as reflected in the expansion of the Antarctic Ice Sheet. This raises the possibility that the encounter could have contributed to that climatic shift in concert with several other factors and ongoing processes, the new study posits.

Further research may be able to test this theory. If unusually high abundances of radioactive elements — which are expected from such substantial dust influx — are indeed ever spotted in our planet's geological record, it would strengthen the study's hypothesis, "because you would have a geological signature and an astronomical perspective that can explain it," study lead author Efrem Maconi, a doctoral student in astrophysics at the University of Vienna, told Live Science.

He and his colleagues described the findings in a paper published last month in the journal Astronomy & Astrophysics. However, spotting the crucial evidence in our planet's geological record — a 14-million-year-old spike in the abundance of a rare iron isotope called iron-60, which is commonly released by supernovas but extremely rare on Earth — will not be easy.

"Looking back in time is hard — no matter if you're doing it in space or Antarctica," Teddy Kareta, an astronomer at the Lowell Observatory in Arizona who was not involved with the new research, told Live Science. "This is a really exciting scenario they've hypothesized, but finding concrete evidence for it mattering for the Earth's climate, or even assessing the increase in dust flux that the solar system experienced, might take quite a bit of time and quite a bit of work from across the sciences."

"We are really talking about yesterday"

Even though the Radcliffe Wave resides in our galactic backyard, at just 400 light-years away, astronomers just noticed it in 2020 thanks to the Gaia telescope's ability to pinpoint the distances and velocities of known star-forming gas clouds, which allowed astronomers to create a 3D map of the solar neighborhood.

Related: 32 alien planets that really exist

Using Gaia's most recent data, Maconi and his colleagues simulated the journey of 56 young star clusters associated with the Radcliffe Wave, tracing both their current orbits in the Milky Way and their pre-birth trajectories, which were inferred from their natal molecular clouds. This allowed the researchers to essentially "go back in time and see where they were in the past in relation to the solar system," Maconi said.

The researchers found that our solar system was at its closest point to the Orion region around 14 million years ago, approaching within 65 light-years of at least two local, dust-heavy star clusters: NGC 1980 and NGC 1981. At the time, our solar system was largely as it is today; Earth and the other planets had been formed for more than 4 billion years. Yet, in cosmic terms, "we are really talking about yesterday," Maconi said.

The simulations suggest that our solar system spent roughly 1 million years within this dense region, coinciding with our planet's "Middle Miocene" transition from a warmer to a cooler climate. That points to the possibility that substantial interstellar dust could have blocked some of the sun's radiation, thereby accelerating the planet-wide cooling, the new study posits.

"It's a big claim to suggest galactic influences on the climate of the Earth," Kareta said. But "the agreement in timing between both events should certainly motivate astronomers and geologists alike to try to assess the likelihood of this scenario in more depth."

An extraordinary claim without extraordinary evidence — yet

There is "reasonable evidence to believe that Earth's voyage around the Milky Way influenced its geology," Chris Kirkland, a geologist at Curtin University in Australia who was not involved with the new study, told Live Science.

For instance, previous research led by Kirkland suggested frequent, high-energy impacts from meteorites during Earth's youth contributed to the production of continental crust on Earth. Kirkland declined to comment on the idea that extraterrestrial dust — as opposed to impacts — may have influenced Earth's climate, however.

In the new study, Maconi and his team noted that the extraterrestrial dust reaching Earth would need to spike by at least six orders of magnitude higher than present-day levels to fully account for planet-scale climate effects. More subtle, indirect influences were more likely at play, and these effects would have unfolded over hundreds of thousands of years, setting them apart from current, human-driven climate change, Maconi said.

Even these differences are difficult to decipher, however, primarily because the geological record for the telltale iron-60 isotope stops at around 10 million years ago. Moreover, iron-60 is unstable, with a half-life of about 2.6 million years, making it especially challenging to detect a signal from an event that occurred 14 million years ago.

"The challenges in peering far back into the history of the Earth's climate clearly limit our ability to assess the likelihood that the Radcliffe Wave had climatological effects at present," Kareta said, "but advances in instrumentation and analysis techniques will likely facilitate us doing better in the future."

There may be other places in our solar system that, unlike Earth's landscape-recycling geological processes, might preserve either the dust itself or the telltale spike of extraterrestrial radioactive elements, Kareta added. These could include deep craters on the moon, specifically near its poles, which receive no sunlight throughout the year and should, in principle, stay cold and stable over long timescales, he said.

"Solar-system-wide processes ought to have left solar-system-wide evidence," Kareta said.

An ambitious new survey by the Hubble Space Telescope provides the first-ever bird's-eye view of all known dwarf galaxies orbiting the Andromeda galaxy.

The results reveal that over billions of years, Andromeda and its family of dwarf galaxies have experienced markedly chaotic interactions — like a game of bumper cars — compared with the relatively placid evolution of the galaxies circling the Milky Way.

The findings, published in The Astrophysical Journal, demonstrate that we may not be able to extrapolate information about other galaxies from our understanding of our own galaxy, the study authors said.

"There's always been concerns about whether what we are learning in the Milky Way applies more broadly to other galaxies," study co-author Daniel Weisz, an associate professor of astronomy at the University of California, Berkeley, said in a statement. "Our work has shown that low-mass galaxies in other ecosystems have followed different evolutionary paths than what we know from the Milky Way satellite galaxies."

At about 2.5 million light-years away, Andromeda is the closest major galaxy to our own, and getting closer; Andromeda and the Milky Way are predicted to collide and merge in about 5 billion years time. To the naked eye, it appears as a faint, spindle-shaped object that covers about the same amount of sky as the full moon. What isn't visible without powerful telescopes and is not well studied is the swarm of three dozen smaller galaxies scattered around Andromeda, like bees around a hive.

Related: The Andromeda Galaxy glows rosy red in gorgeous new Hubble Telescope image

Starting in late 2019, Hubble spent two years cataloging images — as well as measurements of the locations and motions — of three dozen galaxies swirling up to 1.63 million light-years from Andromeda. These data provided Weisz and his team the first comprehensive 3D map of our galactic neighbor's ecosystem. Using this information, the researchers studied the processes that drove the evolution of these dwarf galaxies over nearly 14 billion years of cosmic time.

"Everything scattered in the Andromeda system is very asymmetric and perturbed," Weisz, principal investigator of this Hubble program, said in the statement. "It does appear that something significant happened not too long ago."

That something, the researchers posit, was a collision between Andromeda and a large galaxy a few billion years ago. The possible culprit could be Messier 32, a satellite galaxy of Andromeda and its brightest companion. Astronomers suspect that M32, which is visible to Andromeda's bottom left, is the remnant core from the merger.

"No one knows what to make of that"

Analysis of the Hubble observations also revealed a unique population of galaxies around Andromeda that has not been observed around the Milky Way, according to the new study.

This group began forming most of its stars early on and continued to do so at extremely low rates and for much longer than astronomers would expect. Given the intense gravitational pull of Andromeda, these galaxies should have been stripped of their star-forming gas long ago, similar to what is observed around the Milky Way.

"This doesn't appear in computer simulations," study lead author Alessandro Savino, an astrophysicist at the University of California, Berkeley, said in the same statement. "No one knows what to make of that so far."

The survey also revealed that half of Andromeda's dwarf galaxies orbit in a unique, flat plane, all moving in the same direction — a configuration not observed around other galaxies, including our own.

"That's weird," Weisz said in the statement. "It was actually a total surprise to find the satellites in that configuration and we still don't fully understand why they appear that way."

The galaxies assembled into the "Great Plane of Andromeda" don't exhibit distinguishable traits, such as patterns in star formation. This suggests the plane is not a physically distinct structure but rather a serendipitous configuration whose origins are not yet fully understood, the researchers say.

"There is a lot of diversity that needs to be explained in the Andromeda satellite system," Weisz said in the statement. "The way things come together matters a lot in understanding this galaxy's history."

Radiation from an exploding star may have had a profound effect on the evolution of life on Earth, a new study suggests.

About 2.5 million years ago, the viruses infecting fish in Africa"s Lake Tanganyika underwent a mysterious and rapid explosion in diversity. Yet the exact cause of this change has remained a mystery.

Now, a new study has found that the upswing in the types of viruses found in the lake happened at the same time that our planet was being pummeled by cosmic rays from an ancient supernova — suggesting a possible link between the two events. The researchers published their findings Jan. 17 in The Astrophysical Journal Letters

"It’s really cool to find ways in which these super distant things could impact our lives or the planet"s habitability," lead author Caitlyn Nojiri, an astrophysicist at the University of California, Santa Cruz, said in a statement. "We saw from other papers that radiation can damage DNA. That could be an accelerant for evolutionary changes or mutations in cells."

Lake Tanganyika, in East Africa"s Great Rift Valley, is one of the largest freshwater lakes on the planet; it spans about 12,700 square miles and divides four nations — Burundi, the Democratic Republic of the Congo (DRC), Tanzania and Zambia. The lake is home to more than 2,000 species, more than half of which aren’t found elsewhere. This means that, according to the World Conservation Union, "no place on earth holds such a variety of life."

Related: Scientists detect the most powerful cosmic rays ever — and their unknown source could be close to Earth

One factor that may have driven this diversification is radiation, the study authors propose. Scientists already know that energetic particles in space, known as cosmic rays, can damage the cells of astronauts to cause accelerated aging and that bombardments from these particles could be responsible for the structural preference of biological molecules known as chirality. Yet just how much of a role these space rays played in the history of evolution is relatively unexplored.

To investigate this question, the researchers behind the new study dug up and examined core samples retrieved from the seafloor. They found that it was rich in an isotope of iron called iron-60, which is commonly produced by stellar explosions. By radioactively dating this isotope, they found that the iron-60 within their sample split into two separate ages: one that formed 6.5 million years ago and another that was 2.5 million years old.

To trace the origins of this isotope, the researchers simulated the sun’s movement through the Milky Way. They discovered that roughly 6.5 million years ago, our solar system and star passed through the Local Bubble — a lower-density region of the Milky Way’s Orion Arm that is littered with debris from exploded stars.

The analysis then revealed that the later spike likely came from a supernova, either from a group of young stars in the Scorpius-Centaurus group 460 light-years away, or the Tucana-Horologium group 230 light-years away. By conducting a simulation of a near-Earth stellar explosion, the scientists found that such an event would have rained cosmic rays upon Earth for 100,000 years after the initial blast, creating a pattern matching that of the spike found in the sediment.

If their assumptions are correct and this event actually happened, it would have been powerful enough to penetrate Earth’s atmosphere and snap DNA strands in half — explaining the coinciding explosion of diversity in viruses discovered in Lake Tanganyika.

Although the scientists cautioned that this connection is far from certain, it does raise the possibility that powerful cosmic events may have sculpted life on our planet more significantly than scientists first thought.

"We can't say that they are connected, but they have a similar timeframe," Nojiri said. "We thought it was interesting that there was an increased diversification in the viruses."

The Oort cloud — the mysterious shell of icy objects at the edge of the solar system — might sport a pair of spiral arms that make it resemble a miniature galaxy, new research suggests.

The exact shape of the Oort cloud and how it is affected by forces beyond our solar system have, so far, remained mysterious. Now, researchers have developed a new model that suggests the inner structure of the Oort cloud may look like a spiral disk. They published their findings Feb. 16 on the preprint server arXiv, meaning the work has not been peer-reviewed yet.

The Oort cloud began as the unused remnants of the solar system's giant planets (Jupiter, Neptune, Uranus and Saturn) after their formation 4.6 billion years ago. Some of these remnants are so large, they could be considered dwarf planets.

As these planets began orbiting the sun, their movements kicked the excess material far beyond Pluto's orbit, where they reside today. The Oort cloud's inner edge sits roughly 2,000 to 5,000 astronomical units from the sun, and its outer edge is located between 10,000 and 100,000 AU away. (One AU is approximately 93 million miles, or 150 million kilometers — roughly the average distance from Earth to the sun.)

Related: Planet Nine: Is the search for this elusive world nearly over?

This means that, even at its current speed of around a million miles (1.6 million kilometers) a day, NASA's Voyager 1 spacecraft won't reach the Oort cloud for 300 years and won't exit it for another 300,000.

This extreme distance means the bodies in the cloud are too small and faint — and moving too slowly — to be directly imaged even by the most powerful telescopes. Most of our evidence for it comes from long-period comets — "snowballs" of ice and dust punted from the cloud to orbit around the sun by gravitational perturbations.

Spirals within spirals?

To better understand what the Oort cloud could look like, the researchers behind the new study used information from the orbits of comets and gravitational forces from within and beyond our solar system to build a model of the Oort cloud's structure.

One key to understanding the shape of the Oort cloud is "galactic tide" — the tugs made by stars, black holes and our galaxy's center that have a crucial influence on the Oort cloud's objects but, for objects closer to the sun, are masked by our star's gravity.

When the scientists ran this model through NASA's Pleiades supercomputer, it spit out a structure for the inner part of the cloud (the most densely populated region, located 1,000 to 10,000 AU from the sun) that resembles the spiral disk of the Milky Way. According to the model, the arms of this inner Oort cloud stretch 15,000 AU from end to end.

To confirm this structure through observations, researchers will need to track the objects directly or pick out the light reflected from them from all the other background and foreground sources. Both are incredibly difficult tasks that have yet to have any resources dedicated to them.

But the researchers think that, if we are to understand where comets come from, how our solar system evolved and the cloud's continuing impact on our cosmic neighborhood, it might be a good idea to start looking.

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

Astronomers have used the James Webb Space Telescope (JWST) to take the longest look yet at our galaxy's supermassive black hole — and it's frothing with unusual activity.

Situated 26,000 light-years away in the center of the Milky Way, Sagittarius A* is a gargantuan tear in space-time that is 4 million times the mass of the sun and 14.6 million miles (23.5 million kilometers) wide.

Now, new observations from JWST have revealed a constant stream of flares erupting from the gas swirling around the black hole's mouth. The new findings, published Feb. 18 in The Astrophysical Journal Letters, could help scientists better understand the chaotic nature of the cosmic monsters and how they sculpt their surroundings.

"Flares are expected to happen in essentially all supermassive black holes, but our black hole is unique," lead author Farhad Yusef-Zadeh, an astronomer at Northwestern University, said in an emailed statement. "It is always bubbling with activity and never seems to reach a steady state. We observed the black hole multiple times throughout 2023 and 2024, and we noticed changes in every observation. We saw something different each time, which is really remarkable. Nothing ever stayed the same."

Despite making up a scant 0.0003% of the Milky Way's mass, Sagittarius A* is a powerful engine that periodically sucks matter in before spitting it out at near light speed, creating a feedback process that has shaped our galaxy since its beginnings.

Related: What would happen if a black hole wandered into our solar system?

Scientists think the gigantic black hole started out much like others, born from the collapse of a giant star or gas cloud before gorging on anything that came too close. After swelling to monstrous scales, black holes can even feed on other supermassive black holes.

To conduct the new research, the astronomers pointed JWST's Near Infrared Camera (NIRCam) at Sagittarius A* and observed the space-time rupture's accretion disk — the fast-moving ring of gas and dust wrapped around the black hole — for a total of 48 hours to track how it evolved over time.

During these observations, the astronomers discovered that the black hole was far more active than they assumed. It produced a fireworks display of five to six big flares per day, with several smaller flares erupting in between.

"In our data, we saw constantly changing, bubbling brightness," Yusef-Zadeh said. "And then boom! A big burst of brightness suddenly popped up. Then, it calmed down again. We couldn't find a pattern in this activity. It appears to be random. The activity profile of the black hole was new and exciting every time that we looked at it."

A cosmic fireworks display

It's unclear what's driving the large and small flares. However, the astronomers suggested the eruptions could emerge from two separate processes. The smaller flickers could result from fluctuations that compress the swirling plasma in the black hole's accretion disk to release temporary bursts of radiation, the team proposed.

The larger eruptions, on the other hand, likely emerge from clashing magnetic-field lines within the disk, which release energy in the forms of particles that accelerate away from the disk at close to the speed of light.

By observing the flares at two different wavelengths (2.1 and 4.8 microns), the researchers also made another surprising discovery: that the flares dimmed faster at shorter wavelengths than at longer ones. They believe this could be because the particles in the flares could be losing energy at these higher wavelengths more quickly — a common feature for particles swirling around magnetic-field lines.

To further investigate these questions, the researchers hope to use JWST to observe Sagittarius A* for a longer, uninterrupted 24-hour period. This should reduce the overall noise in their data and help them map out other features in the vortex surrounding the black hole.

"When you are looking at such weak flaring events, you have to compete with noise," Yusef-Zadeh said. "If we can observe for 24 hours, then we can reduce the noise to see features that we were unable to see before. That would be amazing. We also can see if these flares show periodicity (or repeat themselves) or if they are truly random."