Growing damage to the wheels of the Curiosity Mars rover

Close-up of the wheel in the worst condition
Images cropped and reduced to post here. For the original images go here and here.

Survey of wheels

Every few months or so the Curiosity science team uses one of the rover’s cameras to do a survey of the rover’s wheels to track their condition. Since early in the mission they had found the wheels were not holding up as well as expected as they rolled over the rough terrain in Gale Crater and on Mount Sharp, and so they take great care in how they move the rover as well as review the wheels regularly.

A year ago it had appeared that the damage to one particular wheel had increased, to a point where its outer section might even break off.

Yesterday the science team did another survey, as shown in the picture to the right.

The two photos above (found here and here) focus on one particular wheel of that survey, which I suspect is the same wheel that was the focus of last year’s post. After taking the first image on the left the team moved Curiosity so that the other side of the wheel could be photographed. As you can see, the damage is extensive, so much so that it is possible the wheel could collapse entirely in the not-to-distant future.

It also looks like another wheel is beginning to see similar damage (see here and here), though not yet as extreme.

The good news is that Curiosity has six wheels, and that it can continue to travel even with the loss of one or maybe two wheels. It also appears that future terrain might not be so rocky.

The bad news is that this wheel damage is likely the one problem that will likely end the mission, possibly sooner than anyone would like. And from these photographs, that end might be sooner rather than later.

China to begin construction of its Mars sample return spacecraft

China’s state-run press today announced it is about to begin construction of its Mars sample return spacecraft, Tianwen-3, set for launch in 2028.

Based on the announcement, that date seems very unlikely.

China’s mission to retrieve samples from Mars will advance to the flight model development phase within this year, Liu Jizhong, chief designer of the Tianwen-3 mission, said on Thursday. Building on the preliminary technical research and demonstrations, the mission has achieved breakthroughs in key technologies. The engineering team is now focused on developing prototypes, Liu, also a national legislator, told reporters.

The Mars sample return mission is scheduled for launch around 2028, with the goal of returning no less than 500 grams of Martian samples to Earth by around 2031. [emphasis mine]

They only have two years to get the spacecraft built, and it involves “an orbiter, a returner, a lander, an ascender, and a service module.” While China is basing this mission’s design on its successful Chang’e lunar sample return missions, returning samples from Mars is significantly more challenging. The ascent vehicle will have a much greater gravity to overcome, and doing a robotic rendezvous and docking in orbit around another planet millions of miles from Earth has never even been tried.

Curiosity looks uphill at its upcoming travels

Panorama looking up Mount Sharp
Click for original.

Overview map
Click for interactive map.

Cool image time! Since May 2025 Curiosity has been exploring in great detail the boxwork formations located on the lower slopes of Mount Sharp. It is now about to complete those investigations, with the Curiosity science team beginning their planning for moving onward and upward.

The panorama above, enhanced to post here, was taken on March 2, 2026 by the rover’s right navigation camera. It looks uphill along the valley that Curiosity is in toward the mountainous region the rover is targeting. Note that the peak of Mount Sharp is not visible, being more than 25 miles away beyond the horizon and about 15,000 feet higher up.

The blue dot on the overview map to the right mark Curiosity’s present position. The yellow lines indicate roughly the area this panorama covers. The red dotted line marks the rover’s approximate planned route, while the white dotted line indicates Curiosity’s actual travels.

Right now Curiosity is traveling through a geological layer the scientists have dubbed the sulfate unit. The lighter colored hills seen on the horizon have also been identified as sulfate, but believed to be much more pure. The geology there should be very different. Instead of rough and rocky it could be like traveling over soft porous sand. This however is merely a guess on my part, based on imagery of those light-colored hills.

The actual route through those hills however remains unknown. Either the science team has not yet released it, or is still trying to figure out the best way through.

Rocket Lab completes in-space commissioning of two Escapade Mars orbiters

Built by Rocket Lab for NASA and launched in November 2025, the company has now completed the in-space commissioning of two Escapade Mars orbiters and is about to hand operations over to the University of California Berkeley Space Sciences Laboratory (UC-Berkeley).

With both spacecraft now fully commissioned and successfully operating at the Earth–Sun Lagrange Point 2 (L2), Rocket Lab is preparing to hand over operational control to [UC-Berkeley], who will lead science operations at L2 and prepare the mission for its cruise to Mars.

Under contract from [UC-Berkeley], Rocket Lab was selected to design, build, and provide commissioning operations of the two high delta-V Explorer-class interplanetary spacecraft for ESCAPADE. Rocket Lab moved from concept to launch readiness in just over three years, proving commercial collaboration can deliver important science key to supporting future human and robotic exploration of Mars on ambitious schedules and for significantly smaller budgets than typical interplanetary missions. This speed was made possible through Rocket Lab’s vertically integrated spacecraft production, with key components including solar arrays, reaction wheels, propellant tanks, star trackers, radios, avionics, and flight software designed and built in-house.

Launched from Cape Canaveral Space Force Station in November 2025, the twin ESCAPADE spacecraft, known as Blue and Gold, completed spacecraft commissioning and executed two precise trajectory correction maneuvers, placing both spacecraft into their loiter trajectory near L2, approximately 1.5 million kilometers from Earth.

Both spacecraft will be sent on their way to Mars in December 2026 when orbital mechanics between the Red Planet and Earth are right for the journey. Once in Mars orbit the two orbiters will allow for a three-dimensional study of the interaction between the solar wind and Mars’ atmosphere.

Though this is a NASA-funded mission, note that it was built a commercial company and operated not by NASA but by a university. For this reason, it was not only built fast and at a low cost, it uses an innovative flight path that allowed it to be launched anytime and wait in orbit for the right moment to go to Mars. This last innovation provides for a lot more flexibility.

Mars’ fast moving gigantic lava floods

A Martian crater broken by flowing lava
Click for original image.

Cool image time! The picture to the right, rotated, cropped, and reduced to post here, was taken on December 12, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The science team labels this a “crater interrupted by flow.” And what a flow! This unnamed 1.4-mile wide crater was not only filled and partly buried by the flow, that flow was so strong it cut through the crater’s rim at two points, refusing to let that rim block it in any way.

The flow in this case is lava, coming down from the Tharsis Bulge where four of Mars’ biggest volcanoes arose. And that flow was quite vast, as the nearest of those volcanoes, Arsia Mons, is almost 800 miles away. Because of Mars’ relative light gravity, about 39% that of Earth’s, lava on Mars can flow across large distances in a very short time. It might have only taken a few weeks for that flow to cover that 800 miles.
» Read more

The weird landscape of Mars’ death valley

Taffy terrain
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and enhanced to post here, was taken on October 28, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The science team labels this “bands near mesa,” an apt description. What we are looking at is a geological feature unique to Mars, but also unique to only one particular place on Mars, the planet’s death valley, the place in Hellas Basin with the lowest relative elevation of any spot on Mars.

The feature is called taffy terrain. According to a 2014 paper, the scientists posit that this material must be some sort of “a viscous fluid,” naturally flowing downward into “localized depressions.” Those localized depressions however happen to also be at the very basement of Mars.

Note how in some spots the bands appear to have been stripped off, exposing small hollows in which dust has become trapped over time to form ripple dunes.
» Read more

UAE extends mission of its Al-Amal Mars orbiter

Deimos with Mars in the background
Al-Amal’s 2023 image of Deimos, the first good
picture of the moon ever taken. Click for full movie.

The United Arab Emirates (UAE) yesterday announced it is extending the mission of its Al-Amal Mars orbiter (“Hope” in English) to 2028, significantly beyond its initial planned mission of two years.

Launched in July 2020, the Hope Probe successfully entered Mars orbit in February 2021 after a seven-month interplanetary journey, marking a historic achievement as the first Arab nation to reach the Red Planet. Originally designed as a two-year mission to observe and study Mars’ atmosphere, the probe has far exceeded expectations. Since reaching Mars, it has gathered around 10 terabytes of scientific data, shared through more than a dozen datasets with research institutions worldwide.

The probe itself was mostly built by American engineers and organizations, as part of a deal to train UAE students. Once in operation around Mars, the UAE and those students took over almost all operations. It orbits Mars in a very wide orbit, allowing it to study global weather and atmosphere conditions, such as dust storms.

A sinuous Martian ridge of uncertain origin

A sinuous ridge of uncertain origin
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on July 21, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It was posted today by the camera team as a captioned image, with the caption as follows:

The sinuous ridge is approximately 10 meters wide and several kilometers long. The floor surrounding this ridge has been eroding laterally, forming pits and circular features suggestive of removal (sublimation) of subsurface ice. However, landforms such as channels or moraines that might suggest the presence of water or ice are lacking, so the ridge itself does not appear to have formed by fluvial or glacial processes.

Perhaps this curious feature is an exhumed dike formed from magma emanating from Alba Mons in subsurface fractures.

Alba Mons is a gigantic shield volcano to the west.
» Read more

A sculptured Martian landscape

Weird Martian landscape
Click for original.

Cool image time! The picture to the right, cropped and sharpened to post here, was taken on December 4, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The science team labels this landscape “olivine-rich plains”, which is a magnesium iron silicate mineral of some industrial value that is quite common on Earth. Its presence here suggests there could be other valuable minerals in this region.

I post the image because the landscape is so weird and beautiful. The orange color suggests these ridges are covered with dust, if not made of dust entirely. The small areas with a greenish tint that appear to mostly appear on north-facing cliffs could be frost, except this is in the southern hemisphere where north-facing cliffs get more sunlight. As it was autumn when this picture was taken frost is an unlikely explanation.

More likely the green indicates exposures of bedrock or coarser boulders.
» Read more

Windswept Martian volcanic ash?

Volcanic ash on Mars?
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on November 30, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The science team labels this simply as “Features,” the vagueness of which I can understand after digging in to get a better idea of the location and geography.

The location, as shown by the white dot on the overview map below, is inside the Medusa Fossae Formation, the largest volcanic ash field on Mars that is thought to be the source of much of the red planet’s dust. That ash field is large and very deep, and was put down more than a billion years ago when the giant volcanoes of Mars were active and erupting. Thus it is well layered, and many images of that ash field show that layering exposed by the eons of Martian wind scouring its surface.

In this case, that scouring appears to have produced this feathery surface, though the origin of those ridges might have instead come from volcanic flows that are now hardened. Or we could be looking at ancient channels produced by ice or water, though that would have to have been a very long time ago, as this image is located in the Martian dry tropics, where no near surface ice presently exists.
» Read more

New gullies on Mars?

Fresh gullies on Mars?
Click for original image.

Cool image time! The picture to the right, cropped and reduced to post here, was taken on November 6, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The science team labels this image “Fresh-Looking Gullies.” It was clearly taken to study the gullies flowing down the north interior crater wall of this 4.4 mile-wide unnamed crater, about 1,500 feet deep.

What causes these gullies remains an open question. They are found in many places in the Martian mid-latitudes. When first discovered scientists thought they might be related to the sublimation of underground ice. More recent research suggests they are formed by the seasonal dry ice frost cycle that in the high latitudes has carbon dioxide condense to fall as snow in autumn and then sublimate away in the spring.
» Read more

Communications resume with Mars

First images back from Curiosity and Perseverance
Go here and here for the original images.

It appears the solar conjunction that has blocked all communications with the rovers and orbiters for the past three weeks around Mars has now fully ended, with the first new images appearing today from both Curiosity and Perseverance.

The two images to the right were downloaded today. The top image was taken on January 20, 2026 by Curiosity’s front hazard avoidance camera. It appears to be looking uphill in the direction the rover is soon to travel, climbing Mount Sharp. If you look closely you can see the mountain’s higher ranges on the horizon, just to the right of the rover itself.

The bottom picture was actually taken on January 15, 2026 by Perseverance, but was only downloaded today. Both science teams had programmed their rovers to take images throughout the conjunction, scheduled for download when communications resumed.

The picture was taken by Perseverance’s left high resolution camera located on top of the rover’s mast. It looks down at the ground near the rover at the pebbles and rocks that strewn the relatively smooth surface of the terrain west of Jezero crater.

Neither image is particularly ground-breaking. What is important however is that both images prove the rovers are functioning as expected. Expect a lot more data to arrive in the next few days, all gathered during three weeks of blackout.

A 10-mile-long avalanche on Mars

Overview map

A ten mile long avalanche on Mars
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on November 8, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows only three miles of a ten-mile-long avalanche inside the solar system’s largest canyon, Valles Marineris.

The white dot on the overview map above marks the location. In the inset the white rectangle indicates the area covered by the picture to the right. I have indicated the avalanche’s full extent beyond this.

Overall, the landslide fell about one mile along those ten miles. That there are about a dozen small craters on top of the slide tells us this happened quite a long time ago.

As always, the scale of Valles Marineris boggles the mind. Though this avalanche fell about 5,000 feet (the same depth of the south rim of the Grand Canyon), that drop only covered one fifth of Valles Marineris’s depth. At this point, from the rim to the floor the elevation difference is about 23,000 feet, which would place the rim among the 100 highest mountains on Earth. And of course, this is only one small spot in this gigantic canyon that runs 2,500 miles east-to-west, with its depth about the same that entire length.

Mars Reconnaissance Orbiter’s high resolution camera is showing its age

More data drop-outs from MRO

In a cool image earlier this week I noted that, in going through the archive of images most recently sent back from Mars Reconnaissance Orbiter’s (MRO) high resolution camera, it appeared the camera was exhibiting more anomalies, and that we must therefore “be prepared for the loss of this camera and orbiter in the somewhat near future.”

In reviewing the archive again yesterday I noticed even more evidence of deterioration, as illustrated by the picture to the left. Not only are there blank vertical strips of no data, but the color drops out of the color strip halfway down, something I had never seen before. Nor was this the only picture with these issues.

I decided to email Alfred McEwen of the Lunar & Planetary Laboratory in Arizona. who until recently had been the camera’s principal investigator, to find out what is really going on. His answer:

Yes, HiRISE is getting old, just like us. There are 2 issues:

  • 1. Sometimes RED4 fails, leaving a gap in the RED products and color.
  • 2. Bit flips create bad pixels (zeros) in RED1_1 and RED3_1. This can still be mitigated by raising electronics temperatures, and we were just approved for an increase, so this problem should soon be reduced for a year or two. One problem with these increased temperatures is that our calibration isn’t correct, leading to the stripe-ing and strange colors that you noted, although dusty air can also create such issues. The calibration will eventually get updated, but funding is extremely tight.

The first issue explains the drop-out in the color strip. This appears to be a relatively new problem.

The second issue explains the two additional black strips to the right of the color strip. (Bit flips are cases where the radiation of space causes a binary bit to flip randomly from 0 to 1, or visa versa.) Bit flips are something engineers expect in spacecraft, but it appears on MRO they are occurring with more and more frequency.

A third issue, the failure of the electronics unit for CCD RED4 that occurred in August 2023, causes a loss of data in the color strip (see the b&w version of the image above for an example), which the camera team has compensated for using other color filters in that area.

According to McEwen, while the team seems confident the increased temperatures, combined with re-calibration, will fix or reduce issue #2, it is less confident about its impact on the camera’s lifespan.

We wish we knew. We’ve raised temperatures many times and it still works, so we keep raising temperatures incrementally just in case.

All in all, however, McEwen says he expects the high resolution camera to be able to produce images for at as long as MRO operates (at least a decade more), though with time we might be finding the images become narrower and narrower strips.

Martian glacier flowing past small peak

Overview map

Martian glacier flowing past small peak
Click for original image.

Cool image time! The picture to the right, rotated, reduced, and sharpened to post here, was taken on November 24, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

As is proper, the science team labels this vaguely as a “flow obstacle in lobate debris apron.” The obstacle is that small peak. The lobate debris apron is the material flowing past, resembling in almost all details what a glacier looks like on Earth. The scientists use vague terms because they don’t want to trap themselves into a conclusion before it is confirmed.

Nonetheless, based on all the data MRO and other Mars orbiters have been gathering for the past decade, we are almost certainly looking at near-surface ice flowing downhill and past that peak.

The white dot in the overview map above marks the location, on the western end of the 2,000-mile-long mid-latitude strip I label “glacier country,” because practically every image from this region shows features such as this.

The arrow in the inset shows the direction of the downhill grade, dropping from 2,000 to 3,000 feet from the surrounding plateau. The peak itself rises about 130 feet above the flow on the uphill side, but 650 feet above on the downhill side. Apparently the flow piled up somewhat as it hit the peak.

That flow however is likely inactive at this time. Though the researchers have repeatedly monitored the many glacial flows they have found on Mars in the decade since MRO arrived in Mars orbit, so far I have heard of no example showing any movement. And that covers about five Martian years.

These images do prove one thing: Mars is not dry. It has plenty of water near the surface, though locked in ice.

Exposed weirdness on floor of Martian crater

Crazy shapes on floor of Martian crater
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on November 27, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The science team labels this “exposed crater floor materials”. While properly vague, that hardly suffices. This image could easily fall into my “What the heck?!” category of Martian geology that is difficult to understand, no less explain.

The color strip suggests that dust dominates near the top and bottom, though dust is also present in the middle. The patches with the bluish tint in the middle suggests these lighter swirls and patches are bedrock.

Of course, none of that explains the weird shapes of these patches, nor why they exist at all.

Before delving into those weird shapes, we must note the two vertical black strips to the right of the color strip, indicating a gap in data. Such gaps have been appearing more frequently of late, suggesting MRO’s age, almost a decade in orbit around Mars, is beginning to show itself. A failure in 2023 in one filter band of the high resolution camera already leaves blank the color swath in black and white images. These new blank strips indicate further issues, warning us that we must be prepared for the loss of this camera and orbiter in the somewhat near future.
» Read more

New research supports theorized intermittent ocean exiting Mars’ giant Valles Marineris canyon

Theorized ocean from 2019 & 2022 papers
Theorized ocean from 2019 & 2022 papers

Scientists studying the deltas of debris that exist at the base of the cliffs inside Mars’ giant Valles Marineris canyon have concluded the deltas suggest the existence of an ocean there about three billion years ago.

The theorized ocean on the map to the right comes from research published in 2019, with additional support published in 2022. This new work supports those conclusions. From the press release:

At the lower end of the canyon system, so-called “scarp-fronted deposits” were discovered, which are interpreted as “fan deltas”. Fan deltas form where a fan-shaped cone of debris and sand grows directly into a standing body of water. The researchers found that the structures mapped on Mars are very similar to classic deltas on Earth.

…The results also show that the ocean found was at least as large as the Arctic Ocean on Earth. Schlunegger says: “We are not the first to postulate the existence and size of the ocean. However, earlier claims were based on less precise data and partly on indirect arguments. Our reconstruction of the sea level, on the other hand, is based on clear evidence for such a coastline, as we were able to use high-resolution images.”

You can read the new paper here [pdf]., which I strongly suggest as the press release at the link above is very poorly written. The 2019 and 2022 work focused on computer models and the geological features in the region of the theorized ocean, including evidence of possible past tsumanis. This new research focuses on the debris piles at the base of Valles Marineris’ cliffs, all of which appear to end at similar elevations. As this new paper notes:
» Read more

The first preliminary research into landing a Mars helicopter in the Starship landing zone

Map of rotorcraft images in Starship landing zone

In early November 2025 I posted a cool image from Mars Reconnaissance Orbiter (MRO) that had the very provocative label “Characterize Possible Rotorcraft Landing Site”. While this was not the first such image taken by scientists using MRO to scout out potential landing zones for future Mars helicopter missions (see here and here), this particular image was one of several taken recently that were all within the candidate landing zone for SpaceX’s Starship spacecraft, focused specifically on the low Erebus mountain chain that sits within this part of Mars’ northern lowland plains.

In the January image download from MRO, I found another such image, taken on December 1, 2025. The map to the right shows that Starship candidate landing zone, with all the images taken for SpaceX indicated. The inset adds all the recent images taken for this “possible rotorcraft” mission, including the December image and the previous four (here, here, here, and here), with orange representing images already obtained and yellow those requested but pending.

I decided I needed to find out more, and tracked down the scientist who had requested the images, Eldar Dobrea of the Planetary Science Institute in Arizona. In response to my email, he explained:
» Read more

Icy Mars

Overview map

Icy Mars

Today’s cool image once again illustrates the fact that most of Mars Mars is not a dry desert like the Sahara, as most news sources and the general public still believes, but a cold icy place similar to Antarctica, with plenty of near surface ice covering almost the whole planet, except for the dry equatorial regions (the one region we have sent almost all our landers and rovers).

The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on November 26, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows one small section of the floor of an unnamed very old and eroded 82-mile-wide crater located in the northern mid-latitudes of Mars.

That location is indicated by the white dot on the overview map above. This part of the mid-latitudes is a region I dub “glacier country”, a 2,000-mile long strip where practically every image taken there shows very obvious glacial features.

Today’s image is no different. The 2-mile-wide crater in the upper left appears blobby, as if the impact had landed in mud. Its interior is filled with what the scientists believe is glacial debris. The surrounding landscape has a similar appearance, as if the ground was slushy and easily misshapen by seasonal temperature changes. To the southwest of the crater, within what appears to be a surrounding splash apron, there appears to be an eroded drainage channel, likely created by the flow of glacial ice downward.

So, when you read articles telling you Mars is dry and scientists are still hunting for water there, know that whomever wrote that article had no idea what he or she were talking about. The scientists studying Mars know that Mars has lots of water. Except for the tropics below 30 degrees latitude, there is near surface ice everywhere. Their questions revolve instead on figuring out how deep and extensive it is, and how it has shaped Mars’ overall geology.

Second Escapade Mars orbiter completes a delayed engine burn

Engineers have now successfully placed both Escapade Mars orbiters in their parking orbit, the second orbiter completed the required engine burn after it was delayed due to unexpected telemetry during an earlier mid-course correction burn.

That unexpected telemetry suggested the engine was firing at a lower thrust than expected. Today’s update did not provide any additional information as to how the thrust issue had been solved or overcome. All it said was that both spacecraft will fire their engines in November 2026 as planned to head to Mars.

Computer model: A thin ice cap can preserve liquid water on Mars

The parameters used in the computer model
Figure 1 of the paper, showing the parameters
used in the computer model

Using a computer model, scientists have found that a thin cap of ice can act to allow liquid water to exist in lakes on Mars, for extended periods of time.

You can read their paper here. From the abstract:

Working at a localized scale, we combine climate input from the Mars Weather Research & Forecasting general circulation model with geologic constraints from Curiosity rover observations to identify potential climatic conditions required to maintain a seasonally ice-free lake. Our results show that an initially small lake system (10 m deep) with ∼50 mm monthly water input and seasonal ice cover would retain seasonal liquid water for over 100 years, demonstrating conditions close to long-term lake survivability.

From the press release:

In some simulations, the lakes completely froze during colder seasons, whereas in others, the lakes remained liquid and were covered by a thin layer of ice instead of freezing solid. This thin ice acted as an insulating lid, significantly reducing water loss while still allowing sunlight to warm the lake ice during warmer months. As a result of this seasonal cycling, some simulated lakes barely changed in depth over decades, suggesting that they could be stable for longer durations even with average air temperatures below freezing for much of the time.

Because this research is based on computer modeling, it carries great uncertainties. At the same time, it seems to explain the puzzling nature of Martian geology, which has repeatedly suggested the existence of liquid water in the past on a planet that has always been too cold with too thin an atmosphere for liquid water to exist. Data has also suggested that pockets of liquid water might have existed at the base of glaciers. This research aligns with that data.

“Round Deposits” in Martian crater

Round deposits in a crater
Click for original image.

Today’s cool image could also be entered into my “What the heck?!” category of strange Martian geology. The picture to the right, cropped, reduced, and sharpened to post here, was taken on October 19, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The science team labels this as “Round Deposits in Crater.” And yup, that’s what we have, round and flat small mesas inside an unnamed 3,500-foot-wide very shallow crater (no more than 10-20 feet deep) that also appears to be sitting higher than the surrounding landscape. Furthermore, several nearby craters are also raised, with one having its own oblong flat interior mesa. Moreover, the terrain around the crater appears stippled, as if it has been eroding or sublimating away.

The latitude, 37 degrees north, provides the first clue for explaining this weird landscape.
» Read more

Many Martian mysteries in one spot

Many Martian mysteries in one spot
Click for original image.

Just because there are no new images coming back from Mars at this time because the Sun is in the way does not mean we can’t enjoy more cool Martian images. The picture to the right, cropped, reduced, and sharpened to post here, was taken on October 20, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

Labeled merely a “terrain sample,” this means it was taken not as part of any particular research project but to fill a gap in the camera’s schedule. The camera team needs to take regular photographs in order to maintain the camera’s proper temperature, and when there is a long gap they add a terrain sample image to the schedule. Usually they try to pick some target of interest.

In this case the target is this 2,500-foot-high cliff, in which we can see a whole range of Martian geological mysteries. First there are the slope streaks on the cliff, a feature unique to Mars but as yet unexplained. Resembling avalanches, these streaks leave no debris piles at their base, do not change the topography in any way, and can appear randomly throughout the year, fading with time. Though the streaks in this picture are dark, streaks can also be bright.

Both the parallel ridges at the base of the cliff, as well as the cliff itself, are remnants of other major geological events, at least based on present theories.
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The three week communications blackout from Mars has begun

Last image before blackout from Curiosity
Click for original.

Last image before blackout from Perseverance
Click for original.

The two images to the right, both downloaded today (here and here) from the Mars rovers Curiosity (top) and Perseverance, illustrate quite clearly the beginning of the three-week-long communications blackout from Mars caused every two years when the orbits of Earth and Mars places the Sun in-between. As the Curiosity science team noted in a December 22, 2025 update:

This holiday season coincides with conjunction — every two years, because of their different orbits, Earth and Mars are obstructed from one another by the Sun; this one will last from Dec. 27 to Jan. 20. We do not like to send commands through the Sun in case they get scrambled, so we have been finishing up a few last scientific observations before preparing Curiosity for its quiet conjunction break.

Apparently engineers were able to squeeze data and images from Mars for a few extra days, but the incomplete nature of these two pictures — combined with the lack of any other new images today — tells us that the blackout has definitely begun. That they were able to get these additional images after conjunction began suggests the blackout might also end a bit earlier than expected.

Though there is always a concern that something could go wrong while communications are blocked, the risks are small. The science teams for all the Mars orbiters and rovers have dealt with this situation now almost a dozen times since operations became routine there more than a quarter century ago.

The only spacecraft at real risk this conjunction is Maven. Contact was lost from it in early December for unknown reasons, and all efforts to regain communications have so far failed. All engineers know from the little data they have gotten back is it appears to be tumbling. This three week blackout will make any chance of recovery extremely unlikely.

The headwaters of an ancient Martian channel

glacial debris in canyon floor
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on October 24, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The science team labels this simply as “irregular terrain.” It is far more than that. We are looking at a three-mile-wide shallow canyon, with what appear to be eroding glacial features on the canyon floor.

The location is at 35 degrees north latitude, so finding glacial features here is entirely unsurprising, especially because this location is the southern edge of the 2,000-mile-long mid-latitude strip in Mar’ northern hemisphere I label glacier country, because almost every picture shows such glacial features.

In this case, the channel also suggests a much more complex geological history, that could involve flowing water though flowing glaciers are increasingly becoming an alternative explanation.
» Read more

Layers in the biggest canyon in the solar system

Overview map

Layers in the solar system's biggest canyon
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on October 24, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The white dot on the overview map above marks the location, on the lower slopes of the south rim of Valles Marineris, the largest canyon on Mars and by far the largest so far discovered in the solar system. From the rim to the floor the elevation drop here is about 23,000 feet, with the layers shown in the picture to be about 5,000 feet above the canyon floor.

Those layers cover about 500 feet of that elevation drop. Each layer suggests a past event, possibly volcanic eruptions. The curved headwall near the upper left also suggests that some layers were avalanches or mass wasting events flowing downhill to the northeast, one on top of another.

As always, the scale of Valles Marineris is hard to imagine. The rim is 20 miles to the south, but the canyon’s opposite rim is from 140 to 300 miles to the north. You could fit two to five Grand Canyons in this part of Valles Marineris and each would look small in comparison.

Recovering Maven appears increasingly dim

According to a NASA update late yesterday, engineers have still not been able to recover the Maven Mars orbiter since all communications ceased suddenly on December 6, and are now facing a month-long period when the Sun will block all communications with Mars entirely.

The MAVEN team also continues to analyze tracking data fragments recovered from a Dec. 6 radio science campaign. This information is being used to create a timeline of possible events and identify likely root cause of the issue. As part of that effort, on Dec. 16 and 20, NASA’s Curiosity team used the rover’s Mastcam instrument in an attempt to image MAVEN’s reference orbit, but MAVEN was not detected. Additional analysis will continue, but planned monitoring will be affected by the upcoming solar conjunction.

Mars solar conjunction – a period when Mars and Earth are on opposite sides of the Sun – begins Monday, Dec. 29, and NASA will not have contact with any Mars missions until Friday, Jan. 16. Once the solar conjunction window is over, NASA plans to resume its efforts to reestablish communications with MAVEN.

That December 6th tracking data had suggested the spacecraft was tumbling. Though NASA management has not yet given up hope, the longer the spacecraft remains out of touch and in an uncontrolled state, the less chance there will be for it to survive. Batteries will drain, equipment will freeze, and the spacecraft will die. Right now, that appears to be its fate.

No contact with Mars’ rovers for the next month

The Sun is about going to cause a month-long break in communications with Curiosity and Perseverance, the two rovers on Mars.

This communications pause occurs every two years, when the orbits of Earth and Mars align with the Sun in between.

This holiday season coincides with conjunction — every two years, because of their different orbits, Earth and Mars are obstructed from one another by the Sun; this one will last from Dec. 27 to Jan. 20. We do not like to send commands through the Sun in case they get scrambled, so we have been finishing up a few last scientific observations before preparing Curiosity for its quiet conjunction break.

This is not a unique situation. Both rovers have gone through conjunction several times previously. The science teams will place the rovers in secure positions to hold them over during the break.

As for the orbiters circling Mars, it isn’t clear how much their operations will be impacted. The update at the link above makes no mention of them, and my memory says communications with them is less hampered, though reduced somewhat.

Curiosity’s exploration of boxwork on Mount Sharp

Curiosity panorama, December 18, 2025
Click for high resolution panorama. For original images, go here, here, and here.

Overview map
Click for interactive map.

Cool image time! The panorama above was created from three photographs taken on December 18, 2025 (here, here, and here) by the right navigation camera on the Mars rover Curiosity.

The view is north, looking down the flanks of Mount Sharp and across the floor of Gale Crater to its rim about 20 to 30 miles away. In comparing this view with a similar one taken in July, it is obvious that the Martian atmosphere has become far dustier during the last six months. The rim and the mountains beyond are hardly visible now through the haze.

The blue dot on the overview map to the right marks Curiosity’s present position. The yellow lines indicate roughly the area covered by this panorama. The while dotted line indicates the rover’s travels, while the red dotted line its planned routes.

As you can see by both the rover’s tracks in the panorama above and the white dotted line in the overview, Curiosity has been traversing back and forth across the boxwork formation of criss-crossing ridges for more than half a year, as the science team attempts to decipher what caused these ridges and hollows. They have also done some drilling in this effort.

The science team has been getting close to the day it will move on, resuming Curiosity’s climb of Mount Sharp, but they keep finding things amidst this boxwork that requires additional study. For example, consider this from yesterday’s update:
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Ancient Martian drainage into crater lake, now turned into ridges

Inverted channels
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on September 9, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the science team labels “an inverted channel.” From the caption:

Topographic inversion is a process where geologic features that were once low-lying, like impact craters or riverbeds, become elevated over time, like mesas or ridges. In this process, a crater or channel is filled with lava or sediment that becomes lithified [hardened]. If this infill is more resistant to erosion than the surrounding landscape, the less-resistant material can be eroded away by wind or water. The former crater or valley fill, being more resistant, remains elevated as the landscape around it lowers. The original low-lying feature becomes a mesa or ridge.

In this image, an ancient river network and nearby impact craters have undergone topographic inversion. Impact craters contain round mesas within them, and the stream channel is defined by a network of ridges.

The location of this inverted channel makes its history even more interesting.
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