Tag: geology

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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.
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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.
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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.
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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.
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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.

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.
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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.