The sagging flank of one of Mars’ giant volcanoes

The sagging flank of Elysium Mons
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on May 1, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the science team labels a “chain of pit craters in [a] graben”.

A graben is a surface fissure created when the surface either spreads or two sections shift sideways in opposite directions. The chain of pits suggest that there is a larger void below into which the surface is sinking. It is also likely that a lot of the sinking material is volcanic ash, thrown free in an eruption hundreds of millions of years ago, which over the eons has been blown up to this location to settle in the crack to fill it. It is now trapped there, and sinking.

What caused the ground here to shift and create the fissure? In this case, the cause is quite large and massive, in a way that boggles the mind.
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Curiosity’s future travels uphill

The view uphill
Click for full resolution. For original images go here and here.

Overview map
Click for interactive map.

Cool image time! The panorama above, assembled from two pictures taken on June 23, 2025 (here and here) by the left navigation camera on the Mars rover Curiosity, looks to the south and uphill into the canyon that the rover will eventually climb.

The overview map to the right provides context. The blue dot marks Curiosity’s present location, the white line its past travel route, and the red dotted line its future route. The yellow lines indicate the approximate area covered by the panorama.

The science team is presently exploring the boxwork formation on the right, and should spend at least the next month or so there before moving on. As the rover moves up into this canyon we should also expect the science team to spend a great deal of time studying that many layered cliff face to the right.

Eventually the rover will enter those white very hilly regions on the horizon. No route through those hills however has yet been chosen.

The source of a Martian glacial canyon 750 miles long

The source of a Martian glacial canyon 750-miles-long
Click for original image.

Cool image time! The picture to the right, cropped, reduced, sharpened, and brightened to post here, was taken on May 1, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The scientists label this very simply as a “wall on Ausonia Cavis”. Ausonia Cavis — 31 miles long and 20 miles wide at its widest — is one of the many gigantic sinks found in many places on Mars. This particular cliff wall is about 2,000 feet high, though from rim to floor of the sink is closer to 3,000 feet.

The image was likely taken to get a closer look at those gullies flowing down the cliff wall. Previous research of similar cliff walls in this region has found what appears to be seasonal water frost in such gullies, and this image was likely taken to see if more such frost could be spotted here as well.
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Sublimating ice in the Martian dry tropics?

Sublimated ice in the Martian dry tropics?
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on May 3, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled merely as a “terrain sample,” it was likely snapped not as part of any specific research project but to fill a gap in the camera’s schedule so as to maintain the camera’s proper temperature.

When the MRO camera team does this, they try to pick features of interest at the time required, and I think succeed more often than not. In this case, they captured this one-mile-wide unnamed crater that appears to be filled with sublimating glacial debris. Similarly, the plateau surrounding the crater seems to also show signs that some sublimation is occurring of ice just below the surface, producing the areas that appear filled with pockmarks.

The location however suggests that if near surface ice here is sublimating away, it hints at a find of some significance.
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Mars will be mystery until we can walk its surface

A Martian mystery
Click for original image.

Today’s cool image illustrates starkly the limitations of orbital imagery. The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on March 30, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows flow features inside a depression that strongly resemble glacial features, with the downhill grade roughly heading south.

Such features are seen in many places on Mars, almost always in the 30 to 60 degree mid-latitude bands in both the northern and southern hemispheres (see here, here, and here for just three examples. For many more simply search this website using “glacier” or “glacial feature” as search terms).

The problem is that this location is not within that 30 to 60 degree latitude band. In fact, at this location no near surface ice should exist at all.
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The mad mountains of Mars

The mad mountains of Mars
Click for original image.

Overview map
Click for interactive map

Cool image time! The picture above, cropped to post here, was taken on June 10, 2025 by the high resolution camera on the Mars rover Curiosity, and shows some of the stranger terrain found higher up the flanks of Mount Sharp in Gale Crater.

The blue dot on the overview map to the right marks Curiosity’s present position, where it is doing another drilling campaign into the first boxwork geology it has encountered. The white line marks its past travels, while the green dotted line its planned route.

The yellow lines indicate the area seen in the picture above. The wild mountain peaks on the horizon are part of the sulfate-bearing unit that appears very bright in the overview map. The material that makes up this terrain appears to be very easily eroded, based on its features as seen from orbit, as well as Curiosity’s distant view. Whether that erosion was wind, water, or ice, remains undetermined, and is the main question Curiosity will attempt to answer once it gets there, likely in a year or so.

Regardless, the landscape appears almost like it soft sand being washed away.

Where the rover will go next the science team has not yet decided. It will definitely continue uphill, but they do not yet know the route they will take through that sulfate-bearing unit.

The canyon that Curiosity will eventually climb

The canyon that Curiosity will eventually climb
Click for full resolution. For original images go here and here.

Overview map
Click for interactive map.

Cool image time! The panorama above, created from two photographs taken on May 23, 2025 by the left navigation camera (here and here) on the Mars rover Curiosity, looks south uphill into the canyon that Curiosity is eventually going to climb.

The overview map to the right provides the context. The blue dot marks Curiosity’s present position, the white dotted line its past travels, the red dotted line its initial planned route, and the green dotted line its future route. The yellow lines indicate the approximate area seen in the panorama above.

If you look on the horizon to the left, you can see very bright terrain higher up the mountain. This is the pure sulfate-bearing unit that is Curiosity’s next major geological goal. It won’t reach that terrain for quite some time however because first the scientists want to spend some time studying the boxwork geology that Curiosity is now approaching. That boxwork suggests two past geological processes, as yet unconfirmed. First it suggests the ground dried like mud, forming a polygon pattern of cracks that then hardened into rock. Second, lava seeped up from below and filled those cracks. The lava, being more resistant to erosion, ended up becoming the boxwork of ridges as the material around eroded away.

This proposed history however is not proven. They hope to find out when Curiosity gets there.

Meanwhile, despite having traveled almost 22 miles, the rover is more than 25 miles from the peak of Mount Sharp, which remains out of sight. That peak is also about 15,000 feet higher.

Scientists: Jezero Crater’s theorized lake overflowed intermittently four times in the past

The inlet and outlet valleys of Jezero Crater
Click for original image.

Scientists analyzing the Martian geology of the meandering outflow canyon from Jezero Crater, now think it was formed by four different very short-lived events when the theorized lake inside the crater overflowed the crater rim.

The map to the right, figure 1 of the paper (cropped and annotated to post here), provides the context. Two canyons, Sava Vallis and Neretva Vallis feed into Jezero Crater, and one canyon, Pliva Vallis, flows out. From the abstract:

By examining the shape of the valley, we noticed that Pliva Vallis was not like valleys carved by continuous rivers on Earth and propose instead that the valley was carved by at least four episodes of lake overflow. To give a minimum estimate of the duration of these events, we use a numerical model to simulate the overflow of a lake and the incision of a valley. Modeling suggests that the four (or more) episodes identified each incised part of the valley and that each episode lasted a few weeks at maximum.

The researchers also considered whether Pliva Vallis could have been carved by glacial flows, but rejected that possibility partly because “the general morphology of the valley shows a decrease in depth and width downstream, while subglacial channels [on Earth] tend to remain of similar width or become larger, as the flow regime does not decrease downstream.”

These conclusions of course carry a great deal of uncertainty. For one, they are based solely on orbital data. No ground truth exists as yet. Secondly, they assume the geology on Mars behaves in the same manner as on Earth. It could very well be for example that the reason the valley shrinks in size is because its Martian glacier sublimated away as flowed downhill, something that doesn’t happen on Earth.

Regardless, the data strongly suggests that water shaped Jezero in some manner.

Perseverance moves across the barren outer rim of Jezero Crater

Looking back at the rim of Jezero Crater
Click for full resolution. For original images go here and here.

Overview map
Click for interactive map.

Cool image time! While most of the mainstream press will be focusing today on the 360 degree selfie that the Perseverance science team released yesterday, I found the more natural view created above by two pictures taken by the rover’s right navigation camera today (here and here) to be more immediately informative, as well as more evocative.

After spending several months collecting data at a location dubbed Witch Hazel Hill on the outer slopes of the rim of Jezero Crater, the science team has finally had the rover move south along its planned route. The overview map to the right provides the contest. The blue dot marks Perseverance’s present location, the red dotted line its planned route, and the white dotted line its actual travels. The yellow lines mark what I think is the approximate area viewed in the panorama above.

That panorama once again illustrates the stark alienness of Mars. It also shows the startling contrast between the rocky terrain that the rover Curiosity is seeing as it climbs Mount Sharp versus this somewhat featureless terrain traveled so far by Perseverance. Though Perseverance is exploring the ejecta blanket thrown out when the impact occurred that formed Jezero Crater, that event occurred so long ago that subsequent geological processes along with the red planet’s thin atmosphere have been able to smooth this terrain into the barren landscape we now see.

And barren it truly is. There is practically no place on Earth where you could find the surface so completely devoid of life.

Some would view this as a reason not to go to Mars. I see it as the very reason to go, to make this terrain bloom with life, using our fundamental human ability to manufacture tools to adapt the environment to our needs.

Meanwhile, the science team operating Perseverance plans to do more drilling, as this ejecta blanket probably contains material thrown out from the impact that is likely quite old and thus capable of telling us a great deal about far past of Mars’ geological history.

Terraced Martian butte

Terraced Martian butte
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on April 1, 2025, by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The scientists label this as a “Layered Butte.” Seems like a good description. From top to bottom there appear to at a minimum about a dozen terraces, each of which represents a specific geological era on Mars.

I post this mostly because I think it shows us another example of the alien beauty of the Martian landscape. The scientific question of course is what do these layers represent. In a general sense, they indicate that over a long time period one by one these layers were laid down, and then over a likely equally long time period the top layers were worn away, one by one. The mesa is just a random spot where that erosion process was not complete, leaving behind this terraced 400-foot-high tower.
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New research suggests the two types of streaks on Mars are caused by dry events

A Martian slope streak caused by a dust devil?
A Martian slope streak caused by a dust devil? From
data taken in 2023. Click for original image.

Scientists using a computer machine learning algorithm to assembly and analyze global maps of all known slope streaks and recurring slope lineae (RSL) — the two different types of streaks found on Mars whose cause as yet remain unexplained — have concluded that these streaks are likely caused by dry processes, not wet brine seeping from underground.

Slope streaks can occur randomly throughout the year, can be bright or dark, can occur anywhere, and fade with time. Recurring slope lineae instead appear seasonally in the same locations and are always dark.

You can read the published paper here. It essentially provides further details on research that was first announced at a conference in March. From its conclusion:

[O]ur observations suggest that slope streak and RSL formation may be predominantly controlled by two independent, dry drivers, 1) the seasonal delivery of dust onto topographic inclines, and 2) the spontaneous activation of accumulated dust by energetic triggers – wind and impacts for slope streaks, as well as dust devils and rockfalls for RSL.

…Our results underline the fundamental differences between slope streaks and RSL, despite their visual resemblance. Streak and RSL populations occur on opposite hemispheres (north vs south), at different topographic elevations (mostly lowlands vs mostly highlands), in opposite thermal inertia terrain (low vs high), in different wind speed regimes (above-average vs below-average), in dissimilar diurnal thermal amplitude and heat flux terrain (above-average vs average), in different WEH, H2O, H, and water vapor column terrain (average vs below-average), and in terrain that provides suitable (theoretical) conditions for liquid water at different seasons (Ls ~90° vs Ls ~ 270°).

This data suggests both types of streaks form in connection with very fine Martian dust, but the researchers also admit that the actual method in which these avalanche-type streaks form remains unclear. In both cases the streaks cause no change in the topography (sometimes even traveling uphill for short distances), produce no debris piles at their base, as avalanches typically do, and do not appear to have an obvious cause or source at the top of the streak.

The global distribution of dust devils on Mars

Global map of dust devils on Mars
Click for original image.

Scientists reviewing the dust devil tracks in orbital images produced by Mars Reconnaissance Orbiter (MRO) have now created a global map that also provides insight into the ground conditions that cause the dust devils to form. From the abstract:

In the first global study of these tracks using high-resolution satellite images from 2014 to 2018, we find tracks in 4% of the images, mostly near 60° north and south latitudes. These tracks are more common during local summers, especially in the southern hemisphere, coinciding with the peak of Mars’ dust storm season, when active dust devils are also more common. Surprisingly, dust devil track (DDT) formation does not depend on elevation, indicating it is not related to the ambient atmospheric pressure. Instead, they occur in darker areas where surface dust covers coarser material, which is revealed as the dust devil moves past.

The white dots on the map above, figure 5 of the paper, shows those MRO images where dust devil tracks were seen. The redish-orange regions are where the data suggests more dust devils should occur, while the blue areas of regions of few dust devils.

The map also notes the locations where Spirit, Opportunity, and InSight landed. Opportunity clearly landed in a region that had more dust devil activity, which explains why its solar panels were cleaned off so regularly by wind. Spirit did not land in such a region, but somehow it was lucky in getting wind events that cleared its panels of dust. InSight had no such luck, and having landed in a region with little dust devil activity, its panels steadily became covered with dust, eventually forcing the end of the mission.

As the paper notes, “To maximize mission lifetimes, future solar powered assets should favor regions where we have identified numerous [dust devil tracks] and where many active [dust devils] are present.” This proposal makes sense, for many reasons. For one, it shifts missions to higher latitudes where many glacial and near-surface ice features are found. Up until now the science community has sent all the landers and rovers to the Martian dry tropics, which has no such near surface ice. For future colonies it is imperative we begin studying Mars’ wetter regions.

This study provides another practical reason for doing so.

Scientists: Martian gullies formed by CO2 frost, not water flows

Frost on Martian hillside
Dry ice frost on Martian cliffs. From a 2020 post.
Click for full image.

A new analysis of the gullies found on cliffs on Mars, usually on the interior rims of craters, has concluded that carbon dioxide frost is the cause of the erosion, not ancient flows of water.

This conclusion eliminates the need for liquid flowing water in the Martian past, at least in conjunction with gullies. From the paper’s conclusion:

These results show that CO2 frost is capable of producing Martian gully morphologies. Since flows powered by this process are known to be ongoing and capable of transporting the necessary volume of material, it is the simplest explanation for their formation. Variations in the frequency and fluidity of flows could have occurred over time due to variations in the CO2 cycle. CO2-driven gully formation would indicate that there was not necessarily regular, recurring meltwater during high-obliquity periods. This removes a constraint on recent climate, and also addresses a paradox: if obliquity regularly exceeds the current value as generally thought, and if gullies formed via snow melting at high obliquity, the Late Amazonian Epoch should have included regular snowmelt and widespread aqueous processes. Gully formation by CO2 frost processes is consistent with a cold-desert Late Amazonian with rare or small amounts of liquid water and little aqueous weathering, consistent with the observed mineralogy.

…Gullies, one of the most-discussed lines of evidence for liquid water on Mars, may in fact have no direct connection to H2O. CO2 frost-fluidized gully formation also has broader implications for geomorphology, widening an emerging field of new landform types and processes without Earth analogs. Similar processes could occur on other worlds with erodible substrates on steep slopes and volatile ices at their frost point, although we currently lack the high-resolution images needed to test this hypothesis. Such ices include N2 on Pluto and Triton, and SO2 on Io. [emphasis mine]

In other words, though the gullies appear at first glance to our Earth eyes to have been caused by water flowing downhill, in fact the data now suggests the annual CO2 frost cycle of Mars is the prime cause, even in the distant past. No surface water was required. And since no one has yet come up with a good model for liquid surface water even existing in the Martian past (the atmosphere being too cold and thin), this conclusion helps eliminate this conflict.

The paper also notes the lack of water likely eliminates the need for any planetary protection efforts at these gullies, as the lack of water makes the likelihood of any microbiology nil.

As these conclusions are based on lab work and analysis of images, there remains great uncertainty. Nonetheless, the results help reinforce the arguments that the geological features we see on Mars were formed not by flowing liquid water but by other processes, such as glaciers of ice.

Bright material on the high points of a Martian mountain

Bright material on top of a Martian mountain
Click for original image.

Today’s cool image is mostly an example of the present unknowns of Mars. The picture to the right, cropped, reduced, and sharpened to post here, was taken on April 2, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The science team quite rightly labels this vaguely as “bright materials,” referring to the bright rim of that crater as well as the scattered bright patches on the surrounding plain. This vagueness tells us that the scientists don’t have enough data yet to definitively identify this stuff, though they know it is distinctly unique because of its inexplicable bright albedo compared to everything around it.

That the crater rim (as well as all the crater rims in the full picture) exhibit this same brightness suggests this material was excavated from below when the impacts hit. The surrounding patches suggest that erosion has exposed this buried material at these points.
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Seepage coming from under an ancient Martian flood lava flow?

Seepage at edge of lava flow?
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and enhanced to post here, was taken on April 3, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

I have enhanced the image to make it easier to see the details. It appears we are looking at three layers. At the base (on the left side of the picture) is a relatively smooth bottom layer with the highest number of scattered craters. On the top (on the right side of the picture) is a somewhat rough layer with fewer craters.

In between is a middle layer that appears to be seeping out from under the top layer.

The science team seems to agree with my last guess, as they label this image “Possible basal seepage at flow boundary.” The flow boundary is the edge of a lava flood that scientists believe covered a distance of about 1,400 miles at speeds ranging from 10 to 45 miles per hour.
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A Martian river of ice

A Martian river of ice
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on January 26, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The science team labeled it “Looking for Gullies” because the researchers were likely searching for such geological features on the cliff wall that runs down the right side of the picture.

What is more significant however about this picture is the glacier features in the canyon below that cliff. The downhill grade is to the southwest, and it is very evident that the canyon is filled with glacial-type debris, flowing down that grade. Along the base of the cliff the flow seems focused but squeezed, the larger blocks to the west moving slower and thus acting like a wall themselves. In between the flow moves like rapids in a narrow part of a river, albeit in slow motion.
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Curiosity’s recent travels as seen from orbit

The view of Curiosity from orbit
Click for original image.

Oveview map
Click for interactive map.

Cool image time! Using Mars Reconnaissance Orbiter (MRO), scientists have captured a very cool image of Curiosity in its recent travels on Mars. That picture is above, reduced and sharpened to post here.

Taken by the HiRISE (High-Resolution Imaging Science Experiment) camera aboard NASA’s Mars Reconnaissance Orbiter, the image shows Curiosity as a dark speck at the front of a long trail of rover tracks. Likely to last for months before being erased by wind, the tracks span about 1,050 feet (320 meters). They represent roughly 11 drives starting on Feb. 2 as Curiosity trucked along at a top speed of 0.1 mph (0.16 kph) from Gediz Vallis channel on the journey to its next science stop: a region with potential boxwork formations, possibly made by groundwater billions of years ago.

The overview map to the right provides some context. Curiosity’s present position is indicated by the blue dot. The yellow lines indicate the approximate section of its past travels photographed by the picture above.

According to the press release at the link, the science team is now estimating the rover will arrive at the boxwork geology in about a month.

Eroding lava layers in Mars’ volcano country

Eroding lava in Mars' volcano country
Click for original image.

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

The scientists label this picture “enigmatic terrain.” And there are certainly mysteries here. For example, why are there scattered tiny knobs across the surface in the low areas, but not on the higher areas? Also, what caused that top layer to get stripped in places? Was it erosion from wind? Or did some other process cause that layer to vanish in these spots?

Note too that this landscape has few craters. Whatever happened here occurred recently enough that it was able to cover over the impact history from the early solar system that peppered the planets with craters as the planets formed. Though impacts continue even to this day, the impact rate is far less, which allows younger terrain like this to remain largely crater free.

The location provides us some answers, but it still leaves much of this geology a puzzlement.
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Martian ridges that imitate rivers

Martian ridges that imitate rivers
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on February 26, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The scientists describe these features as “dendritic relief features,” an apt description of the thousands of miles of river-like meandering ridges that orbital images have discovered in the past decade scattered across Mars, as noted in 2016:

The inverted channels are similar to those found elsewhere on Mars and Earth. They are made of sand and gravel deposited by a river and when the river becomes dry, the channels are left upstanding as the surrounding material erodes. On Earth, inverted channels often occur in dry, desert environments like Oman, Egypt, or Utah, where erosion rates are low – in most other environments, the channels are worn away before they can become inverted.

The most dramatic example of these Martian ridge rivers are the fernlike ridges in Antoniadi Crater. The ridges to the right however are almost as striking.
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Myriad flows on mountainous inner crater wall on Mars

Myriad flows in a crater rim
Click for original image.

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

That the science team labels this “Monitoring Slopes for Changes on Eastern Terraces of Mojave Crater” is quite understandable. The number of apparent dentritic channels suggests strongly the possibility of change over time, which is why MRO has been used repeatedly to monitor this location, beginning in 2006, when the science team noted this in a caption:

Aptly-named Mojave Crater in the Xanthe Terra region has alluvial fans that look remarkably similar to landforms in the Mojave Desert of southeastern California and portions of Nevada and Arizona.

Alluvial fans are fan-shaped deposits of water-transported material (alluvium). They typically form at the base of hills or mountains where there is a marked break, or flattening of slope. They typically deposit big rocks near their mouths (close to the mountains) and smaller rocks at greater distances. Alluvial fans form as a result of heavy desert downpours, typically thundershowers. Because deserts are poorly vegetated, heavy and short-lived downpours create a great deal of erosion and nearby deposition.

There are fans inside and around the outsides of Mojave crater on Mars that perfectly match the morphology of alluvial fans on Earth, with the exception of a few small impact craters dotting this Martian landscape.

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The mighty scale of Mars’ geology

The mighty scale of Mars
Click for original image.

Today’s cool image is just one more example out of hundreds I have posted in the past decade of the difficult-to-imagine gigantic scale of the Martian landscape.

The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on March 1, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The image title is simple, “Steep Slopes of Olympus Mons Caldera,” and tells us that this cliff face, about 1,300 feet high, is part of the caldera that resides on top of Mars’ largest volcano, Olympus Mons.

The parallel cracks on the plateau above the cliff tell us that the cliff face is slowly separating outward from that plateau, and that at some point in the future the entire wall will collapse downward.

Sounds impressive and big, eh? What the picture doesn’t make clear however is how truly tiny this cliff is in the context of the entire mountain.
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Another “What the heck?!” image on Mars

Another
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on March 2, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The scientists label this “Monitoring Irregular Terrains in Western Arabia Terra.” I label it more bluntly as another one of MRO’s “What the heck?!” images. For all I know, this is nothing more than a discarded Vincent Van Gogh painting, thrown out because even he couldn’t figure out what he was painting.

The best guess I can make, just from the picture alone, is that some of the dark spots are vents from which the white stuff vented at some point, either as small lava or mud volcanoes. As the location is close to the equator, near surface ice is almost certainly not a factor in what we see.

In any case there is no way to reasonably decipher this picture, just by looking at the picture. It is necessary to take a wider view.
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Terraces within one of Mars’ giant enclosed chasms

Overview map

Terraces within Hebes Chasma

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on January 27, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the terraced layers descending down a 7,000-foot-high ridgeline within Hebes Chasma, one of several enclosed chasms that are found to the north of Mars’s largest canyon system, Valles Marineris.

The white dot on the overview map above marks this location, inside Hebes. The rectangle in the inset indicates the area covered by the picture, which only covers the lower 5,000 feet of this ridge’s southern flank.

The ridgeline might be 7,000 feet high and sixteen miles long, but it is dwarfed by the scale of the chasm within which it sits. From the rim to the floor of Hebes is a 23,000 foot drop, comparable to the general heights of the Himalaya Mountains. Furthermore, this ridge is not the highest peak within Hebes. To the west is the much larger mesa dubbed Hebes Mensa, 11,000 feet high and 55 miles long.

The terraces indicate the cyclical and complex geological history of Mars. Each probably represents a major volcanic eruption, laying down a new bed of flood lava. With time, something caused Hebes Chasm to get excavated, exposing this ridge and these layers.

The excavation process itself remains unclear. Some scientists think the entire Valles Marineris canyon was created by catastrophic floods of liquid water. Others posit the possibility of underground ice aquifers that sublimated away, causing the surface to sink, eroded further by wind. Neither theory is proven, though the former is generally favored by scientists.

Another example of the weird taffy terrain in Mars’ death valley

More taffy terrain

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

The scientists label it dimply as “layers in Helles Planitia.” Other scientists have given this strange landscape a much more interesting label, “taffy terrain.” It is found only in the Hellas Basin, the basement of Mars, having the lowest elevation found anywhere on the red planet. 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.” Because of its weird nature I have posted many cool images of it in the past (see here, here, here, here, and here).

Is taffy terrain still viscous, or has it become solidified? That question I think remains unanswered, though pictures taken of the same spot over time do not yet appear to show changes.
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Martian stucco

Martian stucco
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on January 24, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled simply as a “terrain sample,” it was likely taken not as part of any specific research request but to fill a gap in the schedule in order to maintain the camera’s proper temperature.

In this case the camera team got something quite intriguing. The entire terrain is reminiscent of stucco found on the outside walls of southwest homes. What makes even more intriguing is that the stucco appears to be material that has covered the terrain, based on the two craters that appear half-buried by it. Moreover, this picture only captures a small portion of this landscape, which extends like this over an area approximately 40 miles squared.

What caused this strange terrain? As always, the overview map below provides a clue, though no firm answers.
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High ridge down the center of a big Martian crack

High ridge down the middle of a Martian canyon
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on January 27, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled simply as a “terrain sample,” it was likely taken not as part of any specific research project but to fill a gap in the schedule in order to maintain the camera’s proper temperature.

Whenever the camera team needs to do this, they try to find an interesting object to photograph, and often succeed. In this case they focused on the geology to the right. I suspect that at first glance my readers will have trouble deciphering what they are looking at. Let me elucidate: This this a 2.5-mile-wide canyon, about 1,000 feet deep, that is bisected by a ridge about 500 feet high.

On the sunlight walls of this canyon you can see boulders and debris, with material gathered on the canyon floor. The smoothness of the floor suggests also that a lot of Martian dust, likely volcanic ash, has become trapped there over the eons.
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The next time someone tells you Mars lacks water, show them this picture

Lots of near surface ice on Mars
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In the past decade orbital images from Mars have shown unequivocally that the Red Planet is not the dry desert imagined by sci-fi writers for many decades prior to the space age. Nor is it the dry desert that planetary scientists had first concluded based on the first few decades of planetary missions there.

No, what the orbiters Mars Reconnaissance Orbiter (MRO) and Mars Express have clearly shown is that, except for the planet’s equatorial regions below 30 degrees latitude, the Martian surface is almost entirely covered by water ice, though it is almost always buried by a thin layer of protective dust and debris. Getting to that ice will be somewhat trivial, however, as it is almost always near the surface.

The picture to the right, rotated, cropped, reduced, and sharpened to post here, is a perfect example. It was taken on January 31, 2025 by the high resolution camera on MRO. At the top it shows part of a small glacial-filled crater surrounded by blobby ground clearly impregnated with ice. That crater in turn sits on the rim of a much larger very-eroded ancient 53-mile-wide crater whose floor, also filled with glacial debris, can be seen at the bottom of this picture. The wavy ridge line at the base of the rim appears to be a moraine formed by the ebb and flow of the glacial ice that fills this larger crater.

None of these glacial features is particularly unique on Mars. I have been documenting their presence now at Behind the Black for more than six years. Yet, I find still that most news organizations — including many in the space community — remain utterly unaware of these revelations. Any new NASA or university press release that mentions the near-surface ice that covers about two-thirds of the planet’s surface results in news stories claiming “Water has been found on Mars!”, as if this is a shocking new fact from a place where little water is found.

It is very shameful that so many reporters and news organizations are so far out of touch with the actual state of the research on Mars.
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Graceful isolated dunes at the edge of the sea of dunes that surrounds Mars’ north ice cap

Graceful isolated dunes on the edge of the dune sea that surrounds Mars' north pole
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Cool image time! The picture to the right cropped, reduced, and sharpened to post here, was taken on January 29, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). I have also rotated it so north is up. Labeled simply as a “terrain sample,” it was likely taken not as part of any specific research request but to fill a gap in the schedule in order to maintain the camera’s proper temperature.

In this case the timing allowed the camera team to capture this breath-taking picture of these graceful arching dunes sitting in what is likely the near-surface ice sheet that covers much of the red planet’s high latitudes. That sheet is not pure ice, but a complex mixture of ice, dirt, dust, and sand, covered during the winter by a thin mantle of dry ice.

The isolated dunes appear to be ridges sticking up from that flat terrain, but this impression is probably incorrect, based on the location.
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Perseverance looks to the far west

Panorama taken by Perservance, February 28, 2025
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Overview map
Click for interactive map.

Cool image time! The panorama above, rotated, cropped, and enhanced to post here, was taken today by the left navigation camera on the Mars rover Perseverance. It gives us the first really good high elevation view of the mountainous terrain to the west of Jezero Crater

The overview map to the right provides the context. The blue dot marks the rover’s present position, with the white dotted line its past travels and the red dotted line its future planned route. The yellow lines are my approximate guess as to the area covered by the panorama above.

Neither the rover team nor the team running Mars Reconnaissance Orbiter (MRO) that provides the high resolution images of this region have as yet updated the interactive map to show this western region in high resolution. My guess as to why is that the planned route is not yet heading that way (as indicated by the red dotted line). When Perseverance has finished its exploration of the outer slopes of the rim of Jezero Crater and heads west, this fuzzy area on this map will likely be replaced with high resolution data, similar to the rest of the map.

Nonetheless, if you look close, you can distinguish several geological features seen in the panorama, such as the large crater to the right and the ridge line to the left. Beyond are mountain chains and valleys, as well as many additional craters. This is truly a barren and alien place, though it has enormous potential for eventually becoming a friendlier environment.

All that is required is for humans to live there, with the natural desire to make it so.

Exploring the canyons and plateaus of Valles Marineris

Overview map

The canyons inside Valles Marineris
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on November 2, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows just one small section of a ridge that descends deep into the giant canyon Valles Marineris, the largest known canyon in the solar system.

On the overview map above, the white dot inside the rectangle marks the location, in the westernmost section of the part of Valles Marineris dubbed Ius Chasma.

For scale, the nose of this ridge descends about 7,300 feet from the top to the bottom, about half the total descent from the small isolated plateau shown in the inset. That plateau, located in the mountainous region between Ius Chasma and Tithonium Chasma, rises to approximately the same elevation as the canyon’s rims to the north and south.

What this picture shows us is that Valles Marineris on its western end is both more shallow and broken up, forming several canyons and plateaus. As the catastrophic floods that are theorized to have carved this canyon pushed their way east, they carved a deeper gorge, so that about 1,500 miles to the east the canyon walls are considerable higher, from 20,000 to 30,000 feet in some places.

As always, the tourist in me can’t help look at this terrain and envision inns and hiking trails. Imagine homesteading that plateau where you build a hotel and trails. Since I expect much transportation on Mars will be by air, your guests would fly in, land at a heliport, and spend their visit hiking down into the canyons that surround them.

Damn! The future is going to so grand!

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