The hunt for Planet Nine continues as new discoveries make the Solar System’s biggest mystery even harder to solve. Is there a massive undiscovered planet on the outer reaches of the Solar System? The idea has been around since before the discovery of Pluto in the 1930s. Labeled as planet X, prominent astronomers had put [...]
A rare meteorite recovered from the Sahara Desert could be a fragment of a Moon-size body that met a violent end in the earliest days of the solar system.
The post Did A Moon-Size Planet Grow Fast and Die Young in the Early Solar System? appeared first on Sky & Telescope.
NASA pushed its Deep Space Network beyond its limits during the Artemis I mission nearly four years ago. The global array of deep space communications antennas couldn't keep up with the routine demands of 40 robotic science missions and the extraordinary surge required by NASA's Orion space capsule as it flew around the Moon.
The experience in late 2022 reduced or delayed downlinks from several high-profile science missions, including the James Webb Space Telescope and Mars rovers, as the data-hungry Artemis I mission took priority on NASA's communications network. And that was before the first Artemis mission with astronauts onboard. When Artemis II launched April 1, NASA called upon the Deep Space Network (DSN) again to connect Mission Control to the Orion capsule as it soared more than a quarter of a million miles from Earth.
With a crew of four flying inside the spacecraft, the agency's appetite for data from Orion on Artemis II was even higher than it was on Artemis I. But at a little more than nine days, the Artemis II mission was shorter than the 25 days Artemis I spent in space, helping alleviate the communications overload. Artemis I also launched 10 small CubeSats into deep space, many of which required tracking and telecom services from the DSN. Artemis II carried fewer CubeSats.
© NASA/JPL-Caltech
NASA pushed its Deep Space Network beyond its limits during the Artemis I mission nearly four years ago. The global array of deep space communications antennas couldn't keep up with the routine demands of 40 robotic science missions and the extraordinary surge required by NASA's Orion space capsule as it flew around the Moon.
The experience in late 2022 reduced or delayed downlinks from several high-profile science missions, including the James Webb Space Telescope and Mars rovers, as the data-hungry Artemis I mission took priority on NASA's communications network. And that was before the first Artemis mission with astronauts onboard. When Artemis II launched April 1, NASA called upon the Deep Space Network (DSN) again to connect Mission Control to the Orion capsule as it soared more than a quarter of a million miles from Earth.
With a crew of four flying inside the spacecraft, the agency's appetite for data from Orion on Artemis II was even higher than it was on Artemis I. But at a little more than nine days, the Artemis II mission was shorter than the 25 days Artemis I spent in space, helping alleviate the communications overload. Artemis I also launched 10 small CubeSats into deep space, many of which required tracking and telecom services from the DSN. Artemis II carried fewer CubeSats.
© NASA/JPL-Caltech
Planetary scientists analyzing a lunar meteorite known as Northwest Africa (NWA) 12593 have uncovered evidence of an asteroid impact that occurred 3.5 billion years ago on the Moon, helping to reconstruct a period of intense bombardment that left lasting marks across the inner Solar System.
The post Lunar Meteorite Preserves Evidence of Colossal Asteroid Strike appeared first on Sci.News: Breaking Science News.
Eugene Parker, pioneer of theoretical solar and plasma astrophysics, was born June 10, 1927. Parker revolutionized the field of heliophysics, notably by first proposing the existence of the solar wind — a stream of charged particles ejected from the Sun — in 1958. His theory was confirmed by Mariner II in 1962. Among many otherContinue reading "June 10, 1927: The birth of Eugene Parker"
The post June 10, 1927: The birth of Eugene Parker appeared first on Astronomy Magazine.
A rare meteorite found in the Sahara Desert has revealed evidence of a giant ancient world that once existed in our solar system but later disappeared. Scientists believe this lost world formed about 4.5 billion years ago, during the early days of the solar system. It may have been as large as the Moon or […]
The post Rare Sahara meteorite uncovers a hidden planet from the early solar system appeared first on Knowridge Science Report.
Using the SETI Institute’s Allen Telescope Array, a 42-element radio interferometer at Hat Creek Radio Observatory in Hat Creek, California, astronomers probed 3I/ATLAS for artificial radio transmissions but found only human-made interference.
The post Astronomers Scan Interstellar Object 3I/ATLAS for Alien Radio Signals appeared first on Sci.News: Breaking Science News.
NASA has ended its attempts to reconnect with the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft and begun decommissioning the orbiter, closing the book on a mission that spent over a decade studying how Mars lost its atmosphere. At a June 3 media conference, NASA officials announced that an anomaly review board — which wasContinue reading "NASA fails to reestablish contact, decommissions MAVEN"
The post NASA fails to reestablish contact, decommissions MAVEN appeared first on Astronomy Magazine.
A new study finds that Uranus' moons almost certainly didn't survive the solar system's violent early chaos intact.
Editor’s Note: Astrobites is a graduate-student-run organization that digests astrophysical literature for undergraduate students. As part of the partnership between the AAS and astrobites, we occasionally repost astrobites content here at AAS Nova. We hope you enjoy this post from astrobites; the original can be viewed at astrobites.org.
Title: Dynamics of Planetary Rings Under Thermal Forces
Authors: Wen-Han Zhou et al.
First Author’s Institution: The University of Tokyo
Status: Published in ApJL
If you ask anyone what their favourite planet is, the answer you’ll most likely hear is Saturn. Why? Why else than the beautiful and intricate ring system surrounding the gas giant. The other gas and ice giants in our solar system — Jupiter, Uranus, and Neptune — have ring systems themselves but none quite as striking as Saturn’s. Would it surprise you to learn that astronomers’ best models have not yet totally explained why Saturn’s rings look the way they do?
In contrast, it may not surprise you to hear that people have been trying to explain the rings for as long as we have seen them with telescopes. We now know that planetary rings are collections of relatively small particles (think micrometre up to metre sized), most likely having once been the material of a larger body that was disrupted either by collisions or tidal forces. This material, due to the gravity of its local planet, is sculpted into a flat disc where more subtle interactions then lead to substructure forming within the disc such as gaps and ringlets. Many of these substructures are explained by well-understood physics — for example gaps being carved by embedded moonlets or resonances sculpting ring edges — though there remain some outstanding problems in our understanding.
The authors of today’s article set their sights on the problematic inner edge of Saturn’s A ring (Figure 1). They describe some mechanisms — namely the collisions of micrometeoroids within the rings — by which a sharp ring edge can be maintained, but there exists a gap in the understanding of how such an edge can form in the first place. All hope is not lost, though, as today’s authors reintroduce a physical process they call the “eclipse–Yarkovsky” effect, which seems to explain these phenomena.
Figure 1: A horizontally sliced image of Saturn’s rings shows the rich substructure and gaps within the various rings. Saturn, which is not shown here, would be to the left of the image. The authors of today’s article are particularly concerned with the bright and sharp inner (left side) edges of the A and B rings. Click to enlarge. [NASA/JPL/Space Science Institute]
The idea behind this process revolves entirely around light. When sunlight hits a particle within a planetary ring, non-absorbed sunlight imparts a little “bump” onto a particle, ever so slightly altering its trajectory. At the same time, some of the sunlight is absorbed into the particle, which heats it up; light is soon re-emitted via thermal radiation, which, again, can slightly change the trajectory of these tiny particles. From a point on the surface of each ring particle (see rightmost side of Figure 2), the photons from this thermal radiation are all emitted in random directions; however, across the whole surface of the particle there is a net force! These tiny particles are spinning, and so the side just near “sunset” is hottest and emitting the most thermal photons. In this way, the pressure from the sunlight plus the thermal radiation of each particle imparts a net torque on the ring itself which changes the angular momentum of the ring.
Figure 2: Starlight is the main source of light onto the particles that make up a planetary ring (right panel) though reflected light from the planet’s surface hits it too. This light “heats up” the ring and forms an asymmetry as the ring is eclipsed by the planet, which produces a net force. [Zhou et al. 2026]
After today’s authors detailed all of the math involved in this process (and there is a lot), they put it into practice to try to help explain Saturn’s curious rings. Including the eclipse–Yarkovsky effect together with other known effects that drive ring evolution allowed them to reproduce the optical depth profile (how thick the ring looks) of Saturn’s A ring better than ever before (notably the sharp inner edge in Figure 3). On top of this, the effect provides another avenue for moonlet formation in the outer edges of ring systems as the positive torque from the effect drives material out toward and away from the Roche limit.
Figure 3: The authors try to explain the current structure of Saturn’s A ring by initialising it with a Gaussian profile of optical thickness versus radius (black dot-dashed line) and evolving it for 81 million years under different effects. When viscous effects are included (blue dashed line), the ring spreads out, but it’s only when the eclipse–Yarkovsky (EY) effect is included (red line) that the model closely matches the observed data (grey line). [Zhou et al. 2026]
Original astrobite edited by Wasi Naqvi.
About the author, Ryan White:
I am a first-year PhD student at Macquarie University in Australia, working mainly on binary/multiple systems with massive stars (Wolf–Rayets in particular!). Outside of study, I’m probably drinking coffee, baking, reading, or going for a run. You can also find me procrastinating on Bluesky @astroryan.bsky.social.
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Why does one side of the Moon have a lot of craters, while the other side does not? Stephen LogesBrooksville, Florida When the first photos of the Moon’s farside were obtained, people usually expressed the difference between the back and the front in terms of “more craters on the back.” It might be better toContinue reading "Why does one side of the Moon have a lot of craters, while the other does not?"
The post Why does one side of the Moon have a lot of craters, while the other does not? appeared first on Astronomy Magazine.
A meteorite discovered in Africa could be evidence of a lost protoplanet that once orbited our Sun, according to researchers at the University of Colorado at Boulder.
In a recent paper published in Earth and Planetary Science Letters, the team revealed evidence of an ancient protoplanet that may have been as large as Mars based on simulations of how the meteorite sample may have formed.
The four-and-a-half-billion-year-old world carried an unexpected geological makeup, which the researchers say casts doubt on common assumptions regarding planetary evolution.
According to the UC Boulder team, the massive protoplanetary body collided with another object four and a half billion years ago, shattering it completely. This is the first definitive evidence of a lost protoplanet in our solar system, based on analysis of the angrite meteorite NWA 12774, a shard of that planetary embryo recovered from the Sahara Desert.
“It’s incredible to think there was once a world this large,” said lead author Aaron Bell, an assistant research professor in the Department of Earth Science at CU Boulder. “We only know it existed because a few fragments of it happened to land on Earth. These meteorites preserved evidence of a completely different pathway through which early planets developed.”
Angrites, a rare type of volcanic rock, serve as a record of our solar system’s distant past. These rocks began forming only a few million years after the solar system’s birth, making them valuable evidence of this early era. However, they are extremely rare and difficult to find.
NWA 12774 is one of only 68 angrite samples identified among more than 80,000 meteorites cataloged by scientists. Given its rarity, the discovery could potentially reshape how researchers understand these ancient rocks.
Until now, scientists had assumed that angrites originated from relatively small asteroids less than 124 miles (200 kilometers) wide, based largely on their chemical composition. Large rocky planets such as Earth and Mars contain significant amounts of silicon dioxide, while angrites contain very little of the compound.
Researchers began to reconsider those assumptions when they identified clinopyroxene in the meteorite sample. This mineral, commonly found in Earth’s crust and mantle, appeared unusually rich in aluminum, suggesting that it formed under significant pressure deep within a planetary body.
To investigate this unusual characteristic of NWA 12774, the University of Colorado Boulder team recreated the conditions under which the sample could have formed. Their analysis revealed that pressures of at least 17.5 kilobars were required to produce the aluminum-rich clinopyroxene found in the meteorite. For comparison, one kilobar is roughly equivalent to the pressure at the deepest part of Earth’s oceans, near the bottom of the Mariana Trench.
The researchers’ discovery proved that at least this particular angrite sample could not have formed inside a small meteorite, as a body with a radius of at least 621 miles would be required to generate the pressure needed to produce the crystals.
Additional evidence suggested the parent body may have been even larger. The crystals’ sharp edges and delicate internal structures indicate they likely formed at relatively shallow depths beneath the surface. Reconciling both the high-pressure conditions and the shallow formation depth suggests that the parent body may have ranged in size from the Moon to Mars.
“There are many meteorites sitting in drawers that haven’t been thoroughly studied, so there were likely more of these protoplanets we don’t know about,” Bell said.
Exactly what happened to this ancient world remains uncertain, but researchers believe it was likely destroyed in a massive collision early in the solar system’s history. Fragments of that lost protoplanet may have later contributed material to other bodies, potentially including Earth itself.
“The materials that formed the angrite parent body are fundamentally different from the ingredients of Earth and Mars,” Bell concluded. “It points to a distinct and separate evolutionary path in planetary formation in the early history of our solar system.”
The paper, “High-Pressure Clinopyroxene in Northwest Africa 12774 and New Geobarometric Evidence for a Planetary Embryo-Sized Angrite Parent Body,” appeared in Earth and Planetary Science Letters on July 1, 2026.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.
When the third known object from the galactic space beyond our Sun barreled through the solar system last year, Earth was in a terrible spot to view its flyby. Thankfully, however, a spacecraft that was previously busy mapping Mars took advantage of much better positioning for a closer look.
Astronomers have now observed three interstellar objects as they’ve flown through the solar system: 1I/ʻOumuamua, which shocked astronomers in 2017; 2I/Borisov, which followed in 2019 and behaved almost identically to a solar system comet; and now 3I/ATLAS, which was found buzzing toward the Sun in July 2025. As soon as 3I/ATLAS was spotted, pretty much every telescope on the planet took a look. The data swiftly revealed much that intrigued astronomers: while 3I/ATLAS was behaving essentially like a standard comet, its chemistry was nothing like its solar system counterparts, and its coma and dust outflow were strangely shaped. Among other oddities, it seemed to counterintuitively have a dust tail that pointed toward the Sun.
3I/ATLAS’s path across the sky as seen from Earth versus the clearer line of sight from Mars. The shaded region represents the times where the comet was too close to the Sun for viewing. [Xin Ren et al. 2026]
The Tianwen-1 spacecraft, which entered Martian orbit in early 2021 and has been diligently mapping the Red Planet ever since, has a high-resolution camera that’s normally pointed at the planet’s surface. By spinning the spacecraft around, a team of researchers led by Xin Ren (National Astronomical Observatories, Chinese Academy of Sciences) repurposed the camera to act as a small telescope when 3I/ATLAS flew by. In another cosmic coincidence, 3I/ATLAS happened to pass very near Mars last fall, and this close approach gave Tianwen-1 a great out-of-plane view of the coma. The orbiter managed to capture 57 images of 3I/ATLAS over three days last fall, representing China’s first-ever observations of an object from an asset in deep space.
Stacked images of 3I/ATLAS from the Tianwen-1 orbiter across three epochs; the tail’s apparent shape shifts as the viewing geometry changes. Click to enlarge. [Xin Ren et al. 2026]
As new surveys begin to turn up interstellar interlopers more often, this improvised observation makes a tidy point: the spacecraft already scattered across the solar system can double as a fleet of opportunistic comet-watchers, each offering a view we simply can’t get from home.
“Interstellar Object 3I/ATLAS Observed from Mars by China’s Tianwen-1 Spacecraft,” Xin Ren et al 2026 ApJL 1003 L10. doi:10.3847/2041-8213/ae61b3
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Discovered in December 2024, the roughly 60-meter-wide asteroid 2024 YR4 was initially thought to have a slim chance of striking Earth in 2032. Further observations ruled out an Earth impact but left open the possibility of a Moon impact. New JWST observations show that 2024 YR4 will speed past both Earth and the Moon without a collision.
In April 2025, we featured a Research Note that described March 2025 JWST observations of 2024 YR4 and characterized the asteroid’s size and albedo. At the close of that article, the authors suggested that further JWST observations in early 2026 could help to refine our understanding of the asteroid’s trajectory and determine whether it would strike the Moon.
On 18 and 26 February 2026, JWST carried out those critical observations. In this dataset, the asteroid is bright enough to be detected confidently, and the background is peppered with a sufficient number of reference stars — two factors necessary to determine the precise track of the asteroid as it zipped through space.
Difference between the position of 2024 YR4 determined in this work using three different reduction methods (red, blue, and green circles) and the position drawn from the existing orbit from the JPL Horizons database. The different analysis methods yielded consistent results. [Adapted from De Wit et al. 2026]
Combining the latest JWST observations with existing data stretching back to the asteroid’s discovery, de Wit and coauthors determined a new, highly precise orbit for the object — one that definitively shows that the asteroid will safely pass by the Moon at a distance of 22,900 ± 800 km in 2032. In addition to ruling out the upcoming lunar impact, the team also ruled out any collisions with Earth in the next 100 years. Phew!
Position of 2024 YR4 as seen by JWST in February 2026 (white dashed circle) compared to the asteroid’s location estimated from existing data (red circle). [De Wit et al. 2026]
This work highlights JWST’s potential as a tool for planetary defense. The February 2026 observations detailed here represent the faintest-ever detection of a near-Earth object, and JWST can detect objects far fainter than ground-based telescopes can. This ability allows JWST to observe potentially hazardous asteroids over a larger swath of their orbits, which translates to earlier trajectory estimation — JWST pinned down 2024 YR4’s orbit two years before the asteroid would have become bright enough for ground-based telescopes to do so.
JWST’s role may be even more important for smaller objects that rapidly become undetectable after discovery. De Wit’s team demonstrated this for a 10-meter-diameter 2024 YR4 clone on the same trajectory; for an object of this size, JWST would be able to rule out an Earth impact before the asteroid became undetectable, but ground-based telescopes could not. With surveys from facilities like Vera C. Rubin Observatory and Near-Earth Object Surveyor set to discover hundreds of thousands of new near-Earth objects, JWST’s role as a hazard assessor will likely be in high demand.
“JWST Observations of Asteroid 2024 YR4 Rule Out a 2032 Lunar Impact and Demonstrate a New Regime for Planetary Defense Follow-Up,” Julien de Wit et al 2026 ApJL 1003 L21. doi:10.3847/2041-8213/ae6a95
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