Uranus and Neptune are often described as near-twins, but a new study suggests their chemistry, and possibly their histories, may differ more than expected.
Planetary researchers at the University of Sydney have proposed a new way to classify the soils of Mars, along with a new word for them: areth (the name comes from Ares, the Greek name for Mars).
On October 11, 2026, NASA’s Perseverance rover reached 45.22 km (28.1 miles), edging past the 45.16 km (28.06 miles) logged by NASA’s Opportunity rover, which explored Mars from 2004 to 2018.
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 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.
Researchers developed a model showing how lava-covered planets close to their stars can hold onto their atmospheres, which could help guide the search for life beyond our solar system. Some planets orbit so close to their stars that intense radiation should strip away their atmospheres. Yet several of these scorching, lava-covered worlds still retain thick [...]
After nearly eight years and billions of kilometers of travel, BepiColombo -- a science mission led by ESA in close collaboration with JAXA -- has begun its long-awaited arrival at the smallest and innermost planet in our Solar System.
For almost five decades, Saturn’s north pole has been famous for hosting a bizarre, six-sided jet stream known as the hexagon, a feature first spotted by NASA’s Voyager spacecraft in the 1980s and still churning today.
More than 140 million miles away from Earth, a rare event recently occurred in the twilight skies above Mars, and it was all captured on camera by NASA’s Perseverance rover.
Imagery of a celestial alignment, featuring Earth as it briefly vanished behind the Martian moon Phobos, was revealed in composite photos captured by Perseverance’s Mastcam-Z instrument in early July as the intrepid rover embarked on its 1,907th Martian day, or sol, on the Red Planet.
The rover’s Mastcam-Z camera system, developed by Arizona State University in collaboration with Malin Space Science Systems, was built for capturing high-resolution panoramic zoom imagery of the Martian landscape. Although its main objectives involve its investigations of Jezero Crater and ancient geological features preserved there for eons, which may even include evidence of past microbial life, cases like the recent celestial alignment showcase how the rover’s cameras can also provide unique insights into astronomical events.
A sequence of composite images (after color correction) reveals the irregularly-shaped Martian moon Phobos with Earth, appearing as a tiny point of light, disappearing behind it (Image Credit: NASA/JPL-Caltech/ASU/MSSS/SSI)
A Robot on Mars Captures an Occultation
Captured against fading twilight, our Earthly home appears as little more than a tiny, bright speck of light as it slowly passes behind the irregularly shaped Martian moon, in what astronomers refer to as an occultation.
NASA applied processing to the rare images, which helped to filter out some of the background light, revealing the brief celestial pairing in greater detail. The resulting imagery offers a glimpse of a dark backdrop that now better highlights the motion of Earth and Phobos in their treks through the Martian sky.
A Sunset Unlike Any Other
The image was obtained roughly 40 minutes after the Martian sunset, as the natural orbital path Phobos follows causes it to appear to drift upward in the new sequence of images, while Earth moves diagonally downward, then slips out of view behind the oddly shaped Martian companion.
Imagery with enhanced inset of the Martian moon Phobos with Earth visible behind it (Image Credit: NASA/JPL-Caltech/ASU/MSSS/SSI)
In an annotated version released by NASA, timestamps spanning just 40 seconds illustrate the progression of the event in single frames, offering a look at a sunset unlike any ever seen on Earth.
That isn’t to say that the same effect can’t be seen from our planet, but in reverse: a lunar occultation where Mars passes behind the Moon can also be observed here, under the right conditions.
Occultations are frequently used by astronomers to help study the positions and motions of various celestial bodies in this way. However, seeing one from the surface of another planet is a rare treat, offering a view of Earth as a distant point of light.
In the past, Perseverance has also captured images of a lunar eclipse from its position on the Martian surface, as Phobos was seen passing in front of the Sun. Past imagery collected by NASA’s robotic explorer has also documented appearances of the Martian moon Deimos in the Red Planet’s early morning skies.
Colors of Change on a Red Planet
Although Mars’ characteristic rusty hues are ever-present, the recent imagery also offers a glimpse of other subtle colors seen in the Martian environment, particularly at twilight. With subtle bluish grays that gradually transition to redder tones, the new images offer a more nuanced and colorful look at the Red Planet.
Close up of the original composite images before color adjustments, where Phobos can be faintly seen against the Martian twilight, with Earth appearing as a speck of light behind it (Image Credit: NASA/JPL-Caltech/ASU/MSSS/SSI).
Perseverance has now spent more than five years exploring Mars, and its ongoing discoveries have added a wealth of new information to the growing body of knowledge scientists have collected about our nearby planetary neighbor.
As for the recent imagery the rover captured, such a unique view requires careful timing, along with a bit of good fortune, according to Mark Lemmon, a Mastcam-Z co-investigator at the Space Science Institute in Boulder, Colorado.
“Phobos crosses the Martian sky three times a day, and Earth is visible for months at a stretch,” Lemmon said in a statement, adding that “catching one directly behind the other takes planning and a little luck.”
Additional details provided by NASA about the new imagery can be found here and here.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached atmicah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.
Planetary researchers analyzing images from NASA’s New Horizons spacecraft have found evidence that liquid nitrogen may still be seeping up from beneath the dwarf planet’s giant glacier, Sputnik Planitia, marking the first suggested case of recently flowing liquid on Pluto’s surface.
NASA’s Curiosity rover has stumbled on the largest patch of polygon-shaped ground fractures it has ever seen on Mars, a discovery that could reveal more about the planet’s watery past.
Pluto’s tenuous atmosphere appears to have begun contracting after years of holding steady, according to a new study published in the Planetary Science Journal.
The latest images depicting these unique geometric formations, known as polygonal fractures, were revealed this week by NASA, showing the rugged Martian terrain around the Vallee Grande area covered in the unusual-looking features.
Polygons as Far as the Eye Can See
In Curiosity’s photos captured by the rover between June 19th and 20th, a sprawling web of the Martian honeycombs could be seen spreading across the terrain in all directions.
A field of polygon structures visible across the Martian landscape, as seen from the vantage of NASA’s Curiosity rover (Image Credit: NASA/JPL-Caltech/MSSS).
Ashwin Vasavada of NASA’s Jet Propulsion Laboratory in Southern California and the mission’s project scientist likened the discovery to a “sea” of Martian polygons that he said took the Curiosity team’s breath away.
“We’ve seen a lot of fascinating landscapes through Curiosity’s eyes,” Vasavada said in a statement. “We measured their shapes and chemistry carefully and are hopeful there are clues in the data as to how these features formed.”
Ideas on “Honeycomb” Formation
According to Vasavada and his colleagues, some of these unique structures appear to have formed from mud cracks, although the polygonal shape appears to occur under a range of different conditions on the Martian terrain.
Among the reasons for their appearance, scientists have determined that temperature changes can cause moisture to be squeezed out of sediment layers, producing the characteristic structured appearance.
Long before Mars became the cold, arid world we see in NASA imagery today, lakes and streams used to exist along the base of Mount Sharp, the 3-mile-high mountain that Curiosity has been slowly climbing and studying since 2014. Since beginning its trek, the rover has uncovered chemical traces of the planet’s wetter past, including carbon-based organic molecules considered the precursors to RNA and DNA.
While researchers remain uncertain about whether these compounds are the result of biological processes or simply natural geological conditions, their discovery adds to the mounting evidence for an ancient Mars that once would have held the chemical requirements for life to have once existed there.
Ongoing Discoveries
Curiosity has discovered these unique polygon-shaped features on several occasions in the past, although NASA mission scientists say they’ve never seen as many in a single location.
One of the recent similar discoveries took the Curiosity team by surprise, as images of the region obtained by the Mars Reconnaissance Orbiter (MRO) had not indicated anything unusual about the terrain. Once Curiosity arrived, however, a web of unusual polygon features was revealed in the surrounding terrain.
In another instance in 2025, several areas resembling waffle or honeycomb patterns were spotted by Curiosity’s Front Hazard Avoidance Camera (Front Hazcam) on May 1, 2025.
Additional details about Curiosity’s ongoing studies of the Martian landscape can be found on NASA’s official Curiosity page.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached atmicah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.
A Jupiter-mass object orbiting a brown dwarf could become the first confirmed moon beyond our Solar System. A massive object appears to be circling a brown dwarf in the CD-35 2722 system, but calling it a moon is not straightforward. Unlike moons in our Solar System, it does not orbit a planet. Instead, it travels [...]
A £3 million investment could help secure a leading UK role in NASA’s future search for life on nearby planets. An Earth-like planet orbiting a nearby star would appear as little more than a dim point beside a light source 10 billion times brighter. British astronomers are preparing technology that could help NASA separate that [...]
A giant planet spent more than a decade concealed inside one of astronomy’s most closely watched star systems. Astronomers have discovered a planet named Beta Pictoris d orbiting a young star just 63 light-years from Earth. The gas giant is about 100 times fainter than Beta Pictoris b, the first planet found in the system, [...]
As companies develop large constellations of orbital data center satellites, experts say now is the time to start thinking about some critical space safety topics and rules of the road.
The Chicxulub impact not only plunged Earth into an impact winter but also produced a dust blanket that later overheated the planet, according to new research from Purdue University and the University of Colorado, Boulder.
A new look at more than two decades’ worth of archival data from NASA’s Spirit mission suggests that the Martian soil may hold iron-bearing minerals -- hematite and altered magnetite -- that were too faint for scientists to detect in real time during the mission.