Despite the name, the universe’s white dwarfs can glow in a wide range of colors—even green. For the first time, astronomers have spotted a star that appears green to the human eye, and the reddest ever recorded. These outlier stars help explain how certain white dwarf stars would shine in green, pink, cyan, yellow, and purple if we actually saw them up close in space. These colorful findings are described in a study recently published in the journal RAS Techniques and Instruments.

Looking for the ‘perfect radiator’

White dwarf stars are the dense remnants left behind after stars like our sun reach the end of their lifespan. For most stars, their color gives a hint to their temperature. Cooler stars appear orange, warm stars like our sun look white. The hottest glow pale blue, similar to how a blacksmith’s iron will go from red to orange to white hot. Astronomers believed that white dwarfs followed this same rule. They even earned their name after the earliest examples were surprisingly hot and glowed in a white/pale blue. 

“Most stars, including most white dwarfs, behave like ‘perfect radiators,’ so their colour is set almost entirely by temperature. But nobody had really looked into what else might be possible for white dwarfs,” Mark Hollands, a study co-author and astronomer at the University of Warwick in England, said in a statement. “It turns out these incredibly dense stars can produce colours nobody expected, and some of them genuinely surprised me.” 

According to the team, the key to these colors is density. The atmospheres surrounding the coolest white dwarfs can reach about the same density as water (roughly 1 gram per cubic centimeter). They are also millions of times denser than the sun’s photosphere, the lowest layer of its atmosphere. Under these higher density conditions, any trace elements present (carbon, calcium, sodium, etc.) interact with the surrounding dense helium plasma. As they interact with the plasma, they can absorb light across a wider spectrum of colors than they would at lower densities. This then shifts the star’s color away from the more typical orange, white, and blue.

Unfortunately, no white dwarf sky is close enough for its color to be seen directly. Instead, the team calculated their color from data astronomers routinely collect—a star’s spectrum. The spectrum is a “fingerprint” that’s produced when starlight splits apart by wavelength, similar to how a prism splits sunlight into a rainbow. Astronomers ran these spectra through a computer model of what colors human vision can see to check what color a star’s light would appear to our eyes. 

The first green and the reddest red

The team applied this method to several white dwarfs across the cosmos. They found that their colors fall into distinct groups linked to what makes up a star’s atmosphere. Carbon-rich white dwarfs generally appear pink or purple. Stars enriched with debris from busted asteroids and comets, the remains of old planetary systems, tend to be more yellow. Cooler white dwarfs with atmospheres of mixed hydrogen and helium show a more cyan or pale blue tinge. This cyan-pale blue is caused by hydrogen molecules colliding with helium atoms inside their ultra-dense atmospheres.  

The most striking example is WD J1330+6435. This star is about 7,232 degrees Fahrenheit (4,000 degrees Celsius) and around 284 light-years away from Earth. Over time, it has gathered rocky material from its planetary system. All of this extra material enriched its atmosphere with calcium, lithium, and sodium. The result—a chartreuse green appearance in the team’s models. As far as the researchers are aware, no other star (living or dead) has ever been credibly reported as green.

“The traces of sodium in the atmosphere of this white dwarf absorb the orange part of the spectrum, leaving behind a ghostly green glow,” added Hollands. “Imagine standing on a planet and looking up at a green star. It feels like something out of science fiction.” 

On the opposite end of the spectrum, the team identified what could be the reddest star ever recorded—WD J1011+2845. This white dwarf is only 48 light-years away from Earth, and has a deep convection zone. This zone is full of carbon that’s been lifted up from the star’s core to its surface. The carbon molecules then distort the star’s light so much that almost all of it is squeezed into wavelengths beyond 600 nanometres. This wavelength produces an unusual deep salmon-pink glow.

What are the odds?

The team also studied 151 white dwarfs located within about 65 light-years (20 parsecs) from Earth. Only five of these showed unusual colors, two yellow and three pink. This suggests that about 1 in 30 of the universe’s white dwarfs shine with an unusually colored light. 

The team then measured the color temperature of the remaining 146 white dwarfs. Color temperature is commonly used to describe light bulbs using degrees Kelvin—warm white at 3,000K, cool white at 6,000 K, etc. The median color temperature of the sample was approximately 6,800K, which our eyes perceive as white. This measurement corrects a common misconception that white dwarfs are typically blue. The hotter and bluer white dwarfs are mostly brighter, so they can be seen from further away and are over-represented in surveys that only look at a star’s brightness.

“One in thirty might not sound like a huge fraction, but across the entire population of white dwarfs in the Universe, that is still a lot of oddly coloured stars out there,” added study co-author and University of Warwick astronomer Boris Gänsicke. “Yet if we take the median across a representative population of white dwarfs, we found that the average white dwarf really is white.”

The post Astronomers discover first green star and the reddest star ever recorded appeared first on Popular Science.

It’s true, the moon is shrinking. And astronomers now know how fast it’s contracting. While only satellite observations and the most delicate instruments can detect these shifts, the consequences of this shrinkage means moonquakes can occur anywhere on the lunar surface at a moment’s notice.

A team led by Smithsonian National Air and Space Museum planetary geologist Thomas Watters detailed their findings in a study recently published in The Planetary Science Journal. Researchers used data from NASA’s Lunar Reconnaissance Orbiter Camera (LROC), which has spent over 17 years generating millions of images of the moon’s surface. A shriveling lunar landscape may sound dramatic, but it’s occurring at a glacial pace. Based on these new calculations, the moon’s overall radius has decreased nearly 148 feet over the last 400–800 million years as it continues to cool. That’s about 2.4 to 4.3 inches per million years, or just 0.1 micrometer annually.

Although slow, the incremental activity’s effects are visible everywhere. On Earth, about 90 percent of all seismic activity occurs near the boundaries between lithospheric plates. But unlike its host planet, our moon is encased by a single, shell-like plate. This means interior cooling can generate slips and faults anywhere at any given time. After reviewing images taken by the LROC, the study’s authors tallied over 10,000 visible lunar faults.

“The number of these young faults revealed in LROC images is much greater than I ever imagined,” said Watters. “As the interior of the moon continues to cool and contract, it is expected that the growth of existing faults and formation of new faults continues today.”

While the faults can happen anywhere, some lunar regions are more likely than others to feature them. Areas with the thickest crust have fewer faults, which indicates they may be more stable than other, thinner sections. In addition to better understanding lunar history, the distribution and frequency of moonquakes may also help NASA better plan for a long-term human presence on the moon.

The post The moon is shrinking. Astronomers finally know how fast. appeared first on Popular Science.

NASA’s Perseverance Mars rover has officially traveled 28.10 miles—farther across another planet’s surface than any other vehicle in history. Not only that, but the six-wheeled science lab accomplished this impressive feat almost entirely autonomously and in barely a third the time it took the previous recordholder.

“The original mission called for no more than 12.4 miles of driving. We’ve blown well past that,” Steven Lee, Perseverance and Curiosity project manager at NASA’s Jet Propulsion Laboratory, said in a statement.

Perseverance began operations on Mars on February 18, 2021, after landing in an ancient river delta selected for potential past microbial life called Jezero Crater. Since then, the rover has slowly but steadily made its way across the region, while conducting multiple sediment drilling surveys. These samples are then chemically analyzed using onboard laboratory equipment before the results are sent back to mission specialists at NASA.

Perseverance surpassed the previous travel record of 28.06 miles set by NASA’s Opportunity rover, before its communications with NASA ended on June 10, 2018. However, it took Opportunity nearly 15 years to accrue its distance while Perseverance exceeded the same mileage in less than six years, and on the 2,006th Martian day (sol) of its mission. Perseverance is currently traveling towards an area named Idubi through an expanse nicknamed “Lac de Charmes.” The region near Jezero Crater’s western rim hosts what may be the oldest landscape ever investigated in the solar system. Mars does not feature tectonic plates like Earth, which means its terrain is never eroded and subsumed into the planet’s substrates.

Mission engineers have not spent the last six years remotely steering Perseverance, either. The rover arrived on Mars equipped with a self-piloting system called AutoNav, which constructs 3D maps of the immediate surroundings to flag any potential hazards. AutoNav then charts a route between specific waypoints chosen by NASA specialists back home. Perseverance has completed 90 percent of its total excursion with AutoNav. Opportunity and its sibling rover, Spirit, only relied on a first version of the piloting system about five percent of the time.

Perseverance has a long road ahead of it, if all goes according to plan. In October, NASA approved the first mission extension that will continue the rover’s operations through about the end of 2028.

“With all mobility systems fully operational and favorable extended-ground-life test results, we expect Perseverance to keep adding to this record for many years to come,” added Lee.

The post NASA’s Perseverance Mars rover sets distance record appeared first on Popular Science.

Successfully sending Artemis II astronauts on their historic lunar flyby earlier this year required some of the latest and most precise technologies, but not everything in this mission needed the same intense equipment. As crewmates gazed through Orion’s capsule window at the moon’s eclipse of the sun on April 6, 2026, three of the travelers needed a way to easily sketch some of their preliminary observations. They took turns writing their notes on a shared tablet PC—and NASA has recently highlighted their work with a screenshot of their efforts.

Astronauts Reid Wiseman, Victor Glover, Christina Koch, and Jeremy Hansen had a lengthy list of tasks during their 10-day, 700,000-mile roundtrip. One of the most visually dramatic jobs involved carefully assessing lunar activity while passing across the moon’s dark side from a distance of about 46,000 miles away. The roughly hour-long observation period provided astronauts with an unprecedented opportunity to record meteorite activity.

The tablet screenshot includes notes taken by Wisemen (in blue), Hansen (in red), and Glover (in green) during the moon’s eclipse of the sun. The crew collectively spotted at least five faint flashes of light caused by impacts. According to Wiseman, the first three impacts occurred within about 10 minutes into their observations, while another two happened later during the flyby. Impacts two and four were likely also corroborated by Hansen and Glover.

Since the moon does not have an atmosphere like Earth’s, the lunar surface is regularly bombarded by space rocks. Most of them are comparatively small, but they will still pose a problem for future crewed trips to the surface,especially those stationed in a planned permanent lunar base. The data gathered by Artemis II on April 6 will help NASA better understand these dynamics, and plan for the safest environments possible for their astronauts.

Artemis II’s astronauts safely returned to Earth during a splashdown off the coast of San Diego at 8:07 p.m. EDT on April 11. If all goes as planned, Artemis III’s crew will launch on their mission no earlier than June 2027.

The post NASA shares Artemis II astronauts’ handwritten mission notes appeared first on Popular Science.

This curious cloud requires no solid particles to seed its formation — a theoretical phenomenon that's never been observed until now.

The post A Cloud Forms Spontaneously Over a Mountain on Mars — Here’s Why appeared first on Sky & Telescope.

If a train leaves the station in Exeter, England, headed south toward Newton Abbot five years before the railway line opens, how long until anyone figures out that it didn’t happen? Well, evidently about 155 years. A report on magnetic storms, published in Nature in 1871, described an incident thought to be the earliest recordedContinue reading "Case closed on long-standing space weather mystery"

The post Case closed on long-standing space weather mystery appeared first on Astronomy Magazine.

Detective work by a team of space-weather experts has discovered the truth about a historical event that had been thought to be the first-ever case of technological disruption by geomagnetic activity from the sun, but has now been shown to have taken place seven years later.

From it being too hot or too wet to leaves on the track or cows on the line, there's a fine tradition of what the British public consider to be flimsy excuses for delays on the trains. Yet an 1871 edition of the journal Nature describes a very different event that caused a train departing Exeter, in Devon on the south-west coast of the U.K., to be delayed by 16 minutes: a solar storm that flooded the railway signals' electrical telegraph network with current.

"The Exeter train delay is a fascinating story because it sits right at the point where emerging technologies first began to encounter the realities of the space environment," said Jim Wild, who is a professor of space physics at Lancaster University and also the President of the Royal Astronomical Society, in a statement.

The event has frequently been cited as the first example of a solar storm disrupting technology on Earth, but when a team led by Wild went back through historical records to investigate further, they found that things didn't add up.

The original report in Nature stated that the electrical disturbance occurred at 10:05pm local time on Oct. 18, 1841. However, Wild's team found that particular train line didn't open until 1846.

So, they delved deeper into the history books to figure out the truth.

"Our research has a hint of a detective story — piecing together a wide range of archived records to better understand a historically severe space-weather event," said team-member Mike Hapgood, a space weather expert at RAL Space, which is the UK's National Space Laboratory, in Oxfordshire.

Combining data from railway timetables, old newspapers, plus historic reports of solar observations and the northern lights and digitized geomagnetic data, Wild and Hapgood's team were able to conclude that the most likely date for the train delay was Oct. 18, 1848, which coincided with a strong solar storm that hit Earth.

This revised date knocks it off top spot in the chronological list of such events. The first recorded disruption to electrical technologies is now a disturbance on the Midland railway network, which had lines covering much of the U.K., in March 1847.

"Although this means it is not the earliest recorded space weather impact, it remains one of the first clear examples of solar activity disrupting critical infrastructure," Wild said. "It also demonstrates the value of combining scientific records with contemporary newspaper reports and archival documents when reconstructing historic space weather events."

The case reminds us that space weather has been a hazard to technology and modern systems for a long time, and isn't just a recent problem.

"Society has been experiencing the effects of space weather on technology for almost as long as electrical technologies have existed," said Wild.

The most dramatic example is the aforementioned Carrington event of 1859, representing the most significant solar storm on record as it caused telegraph poles to spark and battery power supplies to be disrupted. By this point, telegraph operators had grown used to electrical disturbances associated with auroral activity, but even the Carrington storm shocked them — quite literally in some cases, as extra current ran down the telegraph lines — with its ferocity. Should a similar event occur today, it would cause huge black outs, knock out power grids, disrupt communications and fry satellites.

"While today's space weather [monitoring] capabilities are far more advanced than anything available in the 1800s, the modern technologies we depend on are also much more vulnerable to solar storms," said Hapgood.

The current solar cycle 25 peaked in Oct. 2024 and we are just beginning to come out of an extended period of maximum activity. However, it remains to be seen how the rest of this cycle will play out before reaching solar minimum in about 2030. We've already seen severe geomagnetic storms caused by space weather in May 2024 — will we experience another powerful storm before the decade is out?

Although the famous Carrington Event of 1859 is often described as the first major space weather event to affect technology, earlier incidents did occur. Historical records show that telegraph systems were disrupted by geomagnetic storms as early as the late 1840s.

The post Study: Famous ‘Space Weather’ Train Delay Actually Happened Seven Years Later appeared first on Sci.News: Breaking Science News.

It started as a routine data-quality check. But as Robert Wagner, a scientist with NASA’s Lunar Reconnaissance Orbiter (LRO), scanned a giant Moon map on his computer screen, an unusually large bright spot circled by a dark halo caught his eye, as it implied that surface material in that area had been shaken up.

“I just stopped, dropped everything, and started looking into what that spot was,” said Wagner, an image-processing specialist from Intuitive Machines who works with data from the Lunar Reconnaissance Orbiter Camera (LROC) system.

By comparing before and after images of the Moon, Wagner realized he had discovered the largest, newly formed crater ever found in the solar system, as scientists reported Wednesday in Science Advances. This discovery highlights the value of NASA’s Moon orbiter data in studying a dynamic landscape as the agency advances a sustained human presence and expanded scientific and commercial activity on the Moon.

Officially named McGetchin after pioneering lunar scientist Tom McGetchin, the crater formed on the Moon’s eastern edge sometime between April 11 and May 22, 2024, after a comet or asteroid the size of a three- to six-story building hit the surface.
 
The crash left a crater, 728 feet wide, that spans the length of two football fields. And at 141 feet deep, the crater could fit three vertically stacked yellow school buses.
 
Scientists estimate that an impact of this magnitude happens on the Moon about once in a century or even longer.

Moon takes some hits

For more than 17 years, LRO has been circling the Moon and using its seven instruments to map the topography, surface composition, temperature, and radiation environment there. The spacecraft’s team has identified at least 1,000 new impact craters throughout the mission and flagged 100,000 more surface changes from an object smashing into the Moon or from the debris that flung out after.

With no atmosphere to slow them or burn them up, space rocks and other objects easily reach the lunar surface. Most are much smaller compared to the object that carved out McGetchin crater. The smallest craters scientists can distinguish from LRO images are about 30 feet wide, the length of a three-story building laid on its side, made by rocks about 43 inches wide, the size of a monster-truck tire. Scientists estimate that impacts of this scale produce about 140 new craters across the Moon each year. But most new ones are made by microscopic projectiles that leave holes too small to identify in orbital images.

With its numerous instruments, the spacecraft can observe changes to the lunar surface that aren’t apparent in the LROC images alone. After the crater was discovered, scientists working with LRO’s thermal instrument, Diviner, made follow-up observations of the site. They found a 4-mile-wide area around the crater that is about 16 degrees Fahrenheit cooler at night than its surroundings.

Reporting in a second paper Wednesday in the same journal, researchers say that the cooling happens because the impact fluffs up the regolith around the crater, making it less dense and therefore less able to retain heat.

The large extent of this “cold spot” is striking, scientists say, because it shows that impacts can modify the Moon’s surface far beyond the crater itself. These physical changes could affect how rover wheels interact with the surface, for instance.

Road to discovery

The LROC system collects images from about 60 miles above the Moon as LRO loops from pole to pole. The system includes two cameras that capture high‑resolution black‑and‑white images and one camera for moderate‑resolution multispectral images. Over the years and thousands of passes, scientists have built maps detailed enough to spot not only new craters, but also landslides, landers, seismic faults, and even hints of lava tubes.

LROC scientists regularly analyze close-up images of small portions of the Moon’s surface taken by the Narrow-Angle Camera. Using these images, they look for changes that are typically less than 30 feet across. But every few years the team searches for large (wider than 150 feet) features by creating global Moon maps and comparing them to older versions.

That’s what Wagner was doing on Oct. 24, 2025, when he came across McGetchin. Using images from LROC’s Wide-Angle Camera, which captures broad views with pixels the size of football fields, he stacked hundreds of “before” and “after” frames with software designed to highlight change. Anything that stayed the same turned gray while anything different showed up as bright or dark patches.

While the process sounds straightforward, spotting real craters requires a lot of manual work. The software flags every tiny shift in lighting or shadow, generating hundreds of false alarms. For this reason, Wagner typically verifies the software, looking for small fuzzy halos around pixel‑wide bright points, which indicate splashes of regolith around a new crater.

Spanning hundreds of pixels, McGetchin stood out immediately. “It was by far the most obvious impact debris pattern I’ve ever seen in one of these images,” Wagner said.

After his discovery, scientists turned to the Narrow-Angle Camera, which takes much sharper views at about 3 feet per pixel. This camera’s close-up images, taken as LRO flew over the impact site again, revealed the crater size, shape, and how the surrounding terrain was affected. These images also helped researchers estimate the size and force of the rock fragment that formed the new crater, details that are expected to appear in a future paper.

Banner image caption: A zoomed-in view of the Moon, with debris around McGetchin crater visible as a white spot circled by a dark halo just right of center of the image (marked with black arrows). This is the view that Robert Wagner saw on Oct. 24, 2025, during a routine data-quality check. Wagner is an image processing specialist for NASA’s Lunar Reconnaissance Orbiter Camera, a system of three cameras. Using images from the Wide-Angle Camera (WAC), which captures broad views with pixels the size of American football fields, he stacked hundreds of images captured by WAC over the last several years with software designed to highlight change. Anything that stayed the same is gray; anything that changed showed up as bright or dark patches. The stripes in the image are due to slight changes in lighting between the older and newer images. This image composite shows an area of the Moon approximately 900 miles across.

The post NASA’s Moon Orbiter Spots New, ‘Once-in-Century’ Moon Crater appeared first on NASA Science.

It started as a routine data-quality check. But as Robert Wagner, a scientist with NASA’s Lunar Reconnaissance Orbiter (LRO), scanned a giant Moon map on his computer screen, an unusually large bright spot circled by a dark halo caught his eye, as it implied that surface material in that area had been shaken up.

“I just stopped, dropped everything, and started looking into what that spot was,” said Wagner, an image-processing specialist from Intuitive Machines who works with data from the Lunar Reconnaissance Orbiter Camera (LROC) system.

By comparing before and after images of the Moon, Wagner realized he had discovered the largest, newly formed crater ever found in the solar system, as scientists reported Wednesday in Science Advances. This discovery highlights the value of NASA’s Moon orbiter data in studying a dynamic landscape as the agency advances a sustained human presence and expanded scientific and commercial activity on the Moon.

Officially named McGetchin after pioneering lunar scientist Tom McGetchin, the crater formed on the Moon’s eastern edge sometime between April 11 and May 22, 2024, after a comet or asteroid the size of a three- to six-story building hit the surface.
 
The crash left a crater, 728 feet wide, that spans the length of two football fields. And at 141 feet deep, the crater could fit three vertically stacked yellow school buses.
 
Scientists estimate that an impact of this magnitude happens on the Moon about once in a century or even longer.

Moon takes some hits

For more than 17 years, LRO has been circling the Moon and using its seven instruments to map the topography, surface composition, temperature, and radiation environment there. The spacecraft’s team has identified at least 1,000 new impact craters throughout the mission and flagged 100,000 more surface changes from an object smashing into the Moon or from the debris that flung out after.

With no atmosphere to slow them or burn them up, space rocks and other objects easily reach the lunar surface. Most are much smaller compared to the object that carved out McGetchin crater. The smallest craters scientists can distinguish from LRO images are about 30 feet wide, the length of a three-story building laid on its side, made by rocks about 43 inches wide, the size of a monster-truck tire. Scientists estimate that impacts of this scale produce about 140 new craters across the Moon each year. But most new ones are made by microscopic projectiles that leave holes too small to identify in orbital images.

With its numerous instruments, the spacecraft can observe changes to the lunar surface that aren’t apparent in the LROC images alone. After the crater was discovered, scientists working with LRO’s thermal instrument, Diviner, made follow-up observations of the site. They found a 4-mile-wide area around the crater that is about 16 degrees Fahrenheit cooler at night than its surroundings.

Reporting in a second paper Wednesday in the same journal, researchers say that the cooling happens because the impact fluffs up the regolith around the crater, making it less dense and therefore less able to retain heat.

The large extent of this “cold spot” is striking, scientists say, because it shows that impacts can modify the Moon’s surface far beyond the crater itself. These physical changes could affect how rover wheels interact with the surface, for instance.

Road to discovery

The LROC system collects images from about 60 miles above the Moon as LRO loops from pole to pole. The system includes two cameras that capture high‑resolution black‑and‑white images and one camera for moderate‑resolution multispectral images. Over the years and thousands of passes, scientists have built maps detailed enough to spot not only new craters, but also landslides, landers, seismic faults, and even hints of lava tubes.

LROC scientists regularly analyze close-up images of small portions of the Moon’s surface taken by the Narrow-Angle Camera. Using these images, they look for changes that are typically less than 30 feet across. But every few years the team searches for large (wider than 150 feet) features by creating global Moon maps and comparing them to older versions.

That’s what Wagner was doing on Oct. 24, 2025, when he came across McGetchin. Using images from LROC’s Wide-Angle Camera, which captures broad views with pixels the size of football fields, he stacked hundreds of “before” and “after” frames with software designed to highlight change. Anything that stayed the same turned gray while anything different showed up as bright or dark patches.

While the process sounds straightforward, spotting real craters requires a lot of manual work. The software flags every tiny shift in lighting or shadow, generating hundreds of false alarms. For this reason, Wagner typically verifies the software, looking for small fuzzy halos around pixel‑wide bright points, which indicate splashes of regolith around a new crater.

Spanning hundreds of pixels, McGetchin stood out immediately. “It was by far the most obvious impact debris pattern I’ve ever seen in one of these images,” Wagner said.

After his discovery, scientists turned to the Narrow-Angle Camera, which takes much sharper views at about 3 feet per pixel. This camera’s close-up images, taken as LRO flew over the impact site again, revealed the crater size, shape, and how the surrounding terrain was affected. These images also helped researchers estimate the size and force of the rock fragment that formed the new crater, details that are expected to appear in a future paper.

Banner image caption: A zoomed-in view of the Moon, with debris around McGetchin crater visible as a white spot circled by a dark halo just right of center of the image (marked with black arrows). This is the view that Robert Wagner saw on Oct. 24, 2025, during a routine data-quality check. Wagner is an image processing specialist for NASA’s Lunar Reconnaissance Orbiter Camera, a system of three cameras. Using images from the Wide-Angle Camera (WAC), which captures broad views with pixels the size of American football fields, he stacked hundreds of images captured by WAC over the last several years with software designed to highlight change. Anything that stayed the same is gray; anything that changed showed up as bright or dark patches. The stripes in the image are due to slight changes in lighting between the older and newer images. This image composite shows an area of the Moon approximately 900 miles across.

Dr. Stephen Kane from the University of California, Riverside and colleagues offer a tidy explanation for one of the Solar System’s enduring puzzles: why Venus, so similar to Earth in size and mass, has no moon at all.

The post New Study Explains Why Venus Has No Moon appeared first on Sci.News: Breaking Science News.

In April, the world watched as four humans circled the Moon for the first time in over 50 years with NASA’s Artemis II mission. On Saturday, Sept. 19, the public is invited to look up again with NASA events across the country, including the International Observe the Moon Night celebration held at NASA’s Goddard Space Flight Center Visitor Center in Greenbelt, Maryland.

International Observe the Moon Night is an annual celebration that brings people together to learn about the Moon and explore our connection to Earth’s nearest celestial neighbor. Since the program began in 2010, people around the world have participated through lunar observations, hands-on activities, artwork, music, and more.
 
At NASA Goddard, this year’s celebration will highlight the agency’s ongoing exploration of the Moon, including the historic Artemis II mission. Visitors can peer behind the scenes to learn more about what it took to make Artemis II’s journey around the Moon a success and discover how Goddard scientists and engineers are helping advance our understanding of the Moon, solar system, and beyond.
 
The event will run from 6 p.m. to 9 p.m. EDT.
 
Throughout the event at NASA Goddard, visitors can take part in interactive hands-on activities, create artwork and crafts, and capture selfies at a photo kiosk. Telescopes will also be set up outside (depending on weather), giving attendees an opportunity to observe the Moon and other astronomical objects up close. Inside the Visitor Center, guests can even see a real Apollo 14 Moon rock on display.

• At 6:30 p.m., Dr. Amanda Nahm, planetary scientist at NASA Headquarters, will explore the lunar science and Moon joy from Artemis II.
• At 7:30 p.m., Ernie Wright, scientific visualizer at NASA Goddard, will offer a more technical look at how scientists use real data to create videos and visualizations of the Moon.

The event will also offer a chance to learn more about the groundbreaking research happening at NASA Goddard as scientists work to unlock the secrets of the Moon with missions like the Lunar Reconnaissance Orbiter (LRO) and explore our solar system and the universe beyond.
 
International Observe the Moon Night at Goddard is free and family friendly. Registration is not required, although registering in advance will help the Visitor Center team plan for the event. The event will take place rain or shine, and free parking is available at the Visitor Center.
 
Additional event details, including registration, accessibility and other logistics: https://www.nasa.gov/goddard/visitor-center/events-and-programs/.
 
For people who cannot travel to Greenbelt, there are opportunities to participate in International Observe the Moon Night from all around the planet. Join lunar observers around the world by observing the Moon with friends and family, attending a virtual event or finding an event in your area. Learn more and register your participation at go.nasa.gov/ObserveTheMoon.
 
International Observe the Moon Night is sponsored by NASA’s LRO mission and the Solar System Exploration Division of NASA’s Goddard Space Flight Center, with support from many partners. The celebration is a way for people to pause and look up at our future destination, as NASA prepares for deep space missions to the Moon and beyond.
 
To learn about NASA’s Artemis program, visit:
https://www.nasa.gov/artemis
 
To learn about LRO, visit:
https://www.nasa.gov/lro

Astronauts could travel back to Earth from Mars using rocket fuel converted directly from the carbon dioxide in the Red Planet's atmosphere, using a technique known as electrochemical reduction, a recent study reports.

It's an old method involving electrolysis, which is the application of an electrical current to drive a chemical reaction, but the new trick produces methane pure enough to be used as liquid propellant. (A number of rocket engines these days burn liquid oxygen and liquid methane — including the Raptors that power Starship, the rocket SpaceX is developing to help humanity get to Mars.)

"The work we're doing is basically taking CO2 and using electricity to convert it into carbon-containing fuels and chemicals," said Carter Racine in a statement. Racine is a Ph.D. student in mechanical engineering at Texas A&M University and a member of the study team, which was led by University of Mississippi chemical engineer Ahmed Badreldin.

"You can't bring up everything you need [on Mars] from Earth, because every additional kilogram adds enormous cost and complexity to launch and escape Earth's gravity," added Badreldin. "So the question becomes, How do we make the fuels and chemicals needed for space exploration from the resources already available at the destination?"

One answer is electrochemical reduction, which takes place in an electrolyzer, with electrons flowing from the negatively charged anode to the positively charged cathode. Water at the anode is oxidized, meaning it loses an electron, which is transferred to the carbon dioxide at the cathode, where one of its atoms gains an electron and becomes what chemists refer to as "reduced" (meaning its oxidation state is lowered). It can then react with the hydrogen and oxygen atoms that have split from the oxidized water molecules.

The anode contains a catalyst, and the choice of material for the catalyst dictates what carbon-based compounds are produced when the reduced carbon reacts with the hydrogen and oxygen. For example, a gold catalyst leads to the production of carbon monoxide (CO), while copper produces more complex compounds including alcohols, ethanol and methane (CH4).

What makes the work of Badreldin's team stand apart from previous experiments is that they have developed a nanometer-scale copper catalyst doped in nitrogen that is able to produce nearly pure methane.

Electrochemical reduction of carbon dioxide has been used to produce methane before, in applications on Earth. The problem is, those methods have produced a lot of byproducts alongside methane. On Earth we have complex equipment that separates the methane from the other unwanted compounds, but astronauts are not going to be able to take such unwieldy devices to Mars when every kilogram counts. That's a problem, because for methane to be used as a liquid propellant in rocket fuel it needs to be pure.

However, the specific copper catalyst used by Badreldin's team is able to preferentially produce methane over other compounds, thereby creating it pure without having to refine it. And there's plenty of carbon dioxide available on Mars to use: While Mars' atmosphere is thin, it is nonetheless composed of 96% carbon dioxide.

Even if astronauts never go to Mars, the usefulness of this technique on Earth is clear. Rather than drilling for this natural gas, we can create methane from the carbon dioxide already in our atmosphere.

"We want to do that because right now many of these carbon-based products ultimately come from virgin fossil resources," said Racine. "If we can make them using captured CO2 and renewable electricity, it could reduce reliance on virgin fossil carbon and help close the carbon cycle."

Consequently, electrochemical reduction has also been suggested for use on Earth as a carbon sequestration technique, drawing carbon dioxide out of our atmosphere where it acts as an unwanted greenhouse gas.

The problem with that is, converting carbon dioxide into methane to be burned as a fuel simply releases that carbon dioxide straight back into the atmosphere in a net-zero cycle. Ideally, we want to lock that carbon dioxide away from the atmosphere for a long period of time, but Badreldin doesn't think the technology is ready yet.

"What we are ultimately interested in is seeing whether we can move beyond simply recycling CO2 and toward pathways that are net-negative," he said. "That means using CO2 as a carbon source while converting it into products where the carbon is stored or used long enough that it is not immediately released back into the atmosphere."

It should be noted that the best way to alleviate climate change is to cease burning all fossil fuels, including methane. However, using methane created from electrochemical carbon dioxide reduction in a net-zero process rather than drilling for it could help during the transition from fossil fuels to renewable resources.

The study reporting this research was published in April in the journal ACS Catalysis.

Is that a footprint on Mars? Sorry to burst your bubble, but no. However, scientists have found a strange feature unlike anything they've seen before on the Red Planet's surface.

What is it?

While NASA's Perseverance rover is the newest addition to the agency's robotic Red Planet fleet, its cousin Curiosity is still going strong and finding strange and unusual things on Mars 14 years after landing.

In new observations captured on Mars' Mount Sharp, the Curiosity team has identified "features unlike quite anything we have seen in the past," Michelle Minitti, deputy principal investigator for Curiosity's Mars Hand Lens Imager (MAHLI), said in a statement.

These mysterious features are a bunch of broad, shallow pits scattered across the Martian bedrock.

Why is it incredible?

While little pits and divots are common to find on the Martian surface, these wide, shallow pits that researchers saw with Curiosity are quite different from surface features that have been seen before.

"The pits of this week were much broader and shallower than past features and were not accompanied by obvious objects that were once in the pits," Minitti said.

The team collected as much data as they could on the strange pits using Curiosity's various instruments, including MAHLI, the Mastcam camera, ChemCam (the Chemistry and Camera complex) and APX (Alpha Particle X-Ray Spectrometer).

They have so far found interesting layers in the pit material that seems chemically different from the main bedrock.

But we will have to wait and see what else researchers might be able to learn about these odd pits. How did they form? How long have they existed? What can they tell us about the history of Mars?

Thousands of planets have been discovered beyond our solar system, offering clues to where life might thrive and whether Earth is truly unique.

The Moon may have emerged largely intact within hours of the colossal impact that shaped its birth. Earth has an unusually large moon for a planet of its size and position in the solar system, yet scientists still do not fully understand how that companion came to exist. Now, researchers from the Southwest Research Institute [...]

It has now been just over a year since the comet 3I/ATLAS first captured the world's attention as the third known object to fly through our solar system from beyond. Astronomers are still learning new things about where exactly it came from.

For the first time ever, they've been able to study charged particles in the tail of the interstellar comet. This has told them that 3I/ATLAS contains more nitrogen than the typical comet from our own solar system — revealing a tantalizing clue about how the strange comet formed.

"Finding that it's so rich in nitrogen tells us it likely formed in extremely cold conditions, far from its home star," Lea Ferellec, a research fellow at Northumbria University, said in a statement.

Ferellec's group used the William Herschel Telescope in Spain's Canary Islands. One of this telescope's instruments is a fiber-optic weave named, well, WEAVE. WEAVE lets astronomers do spectroscopy — which splits incoming light into its spectrum. Different chemical elements absorb and emit different wavelengths of light, marking that spectrum with different characteristic fingerprints. With spectroscopy, astronomers can look at a celestial object's light, pick out the fingerprints, and reconstruct the stuff inside.

Other astronomers have measured 3I/ATLAS with spectroscopy, but they've mostly examined the comet's coma, a shell of gas that forms when the sun’s heat sublimates the comet’s ice into vapor.

Of course, a coma is not the only feature that forms as a comet approaches the sun. Close in, a comet is battered by the torrent of the sun's solar wind, which pushes the comet's material away into a distinctive tail. In the process, the solar wind's high-energy particles strike the comet's molecules and electrify them into charged ions.

If astronomers can identify a tail's ions, they can find chemicals and learn information they can't from the coma alone. This is a tricky task. When fellow interstellar comet 2I/Borisov visited our solar system in 2019, astronomers identified traces of its ions, but they couldn't make out what those ions actually were.

WEAVE, which switched on in 2023, is powerful and sensitive enough to change that. When Ferellec and colleagues turned WEAVE on 3I/ATLAS in late 2025, they could count ions like nitrogen, carbon dioxide and carbon monoxide in the strange comet's tail.

Comparing these figures can hint at where a comet formed. For example, a comet with a higher ratio of nitrogen to carbon monoxide tends to have formed in a colder birthplace. Ferellic's group found that 3I/ATLAS has a much higher ratio than most of the comets that we observe in our solar system.

In particular, Ferellec and colleagues estimate that 3I/ATLAS formed somewhere colder than -240°C. If this comet was born in a distant star system, then, it formed in that system's outer reaches. In other words, 3I/ATLAS likely formed in a place where little of its star's light could touch it.

"This object gives us a rare chance to study material that formed somewhere completely different to our own solar system," Ferellec said in the statement. "Every one of these objects we study helps us understand a little more about how planets form around other stars."

Ferellec and colleagues published their work in the journal Monthly Notices of the Royal Astronomical Society on Sept. 7.

The Solar System’s smallest planet has contracted by nearly 19 km (12 miles) across, as crater debris masked telltale wrinkles on its surface, according to new research led by the German Aerospace Center’s Institute of Space Research.

The post Mercury Has Shrunk Even More than Planetary Scientists Thought appeared first on Sci.News: Breaking Science News.

The discovery of water at the poles of the moon has inspired speculation about whether we can build there – cities, industrial neighborhoods, places where people work and live. But is there enough water, and can we use it efficiently enough? In their new article in Frontiers in Space Technologies, Dr. Martin Elvis and Dr. Jonathan McDowell do the math. Even at the most generous estimates of the available water and recycling efficiency, a city of one million people would only last 100 years before all the water runs out. In this guest editorial, which Frontiers in Space Technologies provided, Elvis breaks down what we can and can't do with the technology available.

The discovery of water in dark craters at the moon's poles has sparked a "moon rush" to establish bases there, and then villages, cities and heavy industry. How sustainable is this rush?

Soon after the moon was formed, asteroids bombarded it, creating its pockmarked topography. Near the moon's poles, there are dozens of crater floors that have not seen direct sunlight in about four billion years. Many of these cryogenically cold "pits of eternal darkness" are below a temperature of 110 Kelvin (minus 262 degrees Fahrenheit), forming "cold traps" in which water ice won't sublimate away by more than a millimeter in a billion years, even in the vacuum at the moon's surface. And there is water to freeze: some of those asteroids brought it along with them. Since 2013 we have known that that water is still there, possibly as much as a billion tons of it, thanks to a succession of moon-orbiting missions that have mapped out likely locations in increasing detail.

The presence of water at the lunar poles changes everything about human visits to the moon. Suddenly it is practical to envisage a "moon village" where people could survive without importing every last bit from Earth. They could grow their own food and have showers and functional toilets, unlike the astronauts on the International Space Station (ISS). This possibility has sparked ambitions from the likes of Jeff Bezos to move heavy industry to the moon and Elon Musk's aims to have "self-growing cities" there. These are enticing visions, but are they attainable?

The good news

We realized that we could make a first feasibility estimate simply by looking at how much power and water a large population would use on the moon, and how long a city of 100,000 or one million people could survive there. How sustainable is a city on the moon?

The good news is that power, even without nuclear reactors, is not a problem. That's because the rims of the craters containing the pits of eternal darkness are in almost permanent sunlight. (That's why they are sometimes, slightly incorrectly, referred to as the "peaks of eternal light.") Up on those highly illuminated rims it would be possible to generate three gigawatts of electricity using kilometer-tall towers covered with photovoltaic arrays. It should be possible to manufacture solar panels on the moon. There's certainly plenty of silicon. This could even make AI data centers on the moon possible, by placing them near these sunny peaks. That would be the start of a true lunar economy.

The bad news

The bad news is that, even assuming a generous one billion tons of water to start with, without recycling the answer to our question of sustainability is that the city would last only a few years. Even in the best-case scenario, with 98% efficient recycling of water — the same as achieved on the ISS — a one-million-person city will run out of water in just over a century. That is a problem for sustainable moon settlement. And today's best estimates of the amount of water on the moon are about 30 times less than a billion tons, shortening the time to water exhaustion by the same factor. This means that even a small city would run dry after just a decade or so. A moon village with a thousand people, or even a town with 10,000 people, would instead be sustainable for several centuries or more.

There are potential solutions. We could improve the efficiency of water recycling by a factor of five or more; lower water usage from new techniques such as vertical farming; import water, probably from accessible asteroids; or, simply, find more water. Of these it may be this last hope that is most promising. Current water surveying techniques do not reach below the surface more than a few meters, while the rubble-like rocks of the surface regolith typically extend tens of meters down and may contain water in the cold traps. If the ambitious plans of the space billionaires are to be realized, then finding more water will be the first step.

Astronomers have found new evidence that 3I/ATLAS, only the third confirmed interstellar object ever detected entering the Solar System from beyond, formed in an extremely cold environment far from any star.

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