Tag: Mars

Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and enhanced to post here, was taken on January 16, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Because an electronic unit for one of this camera’s filters has failed, causing a blank strip in the image center, I have filled in that gap using an MRO context camera image taken October 31, 2015.

The scientists describe this geology as “ridged terrain.” What I see is a surface that was like wet plaster once, and then a giant finger touched it and pulled away quickly, so that as it left some material pulled upward to create random ridges within the depression created by that finger.

These ridges are inside a very very ancient 110-mile-wide crater dubbed Margulis. According to the 2021 poster [pdf] of the scientists who did the first geological mapping of this crater, the crater floor “show remnants of sedimentary materials, suggesting the [crater was] subjected to widespread episodes of resurfacing and denudation.”

Though located in the dry equatorial regions, this ridged terrain suggests it formed suddenly when underground ice sublimated into gas, bursting upward to break the surface when the gas pressure became high enough.
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Click for original image.

In preparing today’s cool image I initially planned to post an picture taken on December 26, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), as it showed a strange series of ridges that almost resembled waves or ripples on a pond.

In digging into MRO’s context camera archive to get the larger context, however, I immediately switched to the photo on the right, cropped, reduced, and sharpened to post here. Taken on December 17, 2010, it shows a much more mysterious and striking set of geological features than the closer view of the high resolution image, with the wave-shaped ridges on its western half but another set of wave-shaped cracks on its eastern half.

Even more intriguing, the arcs for the ridges curve in the opposite direction from the arcs for the cracks. It is almost as if there were two flows moving in opposite directions, right next to each other.
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Click for original image.

Cool image time! The picture to the right, cropped, reduced, and enhanced to post here, was taken on January 12, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Because of a technical issue that leaves a blank strip down the center of recent high-res MRO images, I have filled in that gap using a MRO context camera photo taken on January 12, 2015. The resolution is much less, but by doing so we can see the ground features as a unit.

What are we looking at? According to the scientists, this picture shows “fresh-looking ruptures,” referring to the broken line of sharp tears inside that meandering canyon that almost resemble a fresh wound in flesh. As this location is at 28 degrees south latitude, it lies on the edge of dry equatorial regions, where orbital images have sometimes found hints of a few remaining buried glaciers that are much more common closer to the poles.

In this case it appears the warmer equatorial climate has acted to heat up the buried ice so that it sublimated into gas. At some point the gas pressure caused the surface to burst, much like bubbles bursting on the surface of a pot of simmering tomato sauce, leaving behind these scars.
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Cool image time! The picture to the right, rotated, cropped, reduced, and enhanced to post here, was taken on January 29, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

Though the scientists label this image showing “channels”, what I see is either a vent or a sink, with the channels to the south indicating past flows either coming out of the depression or into it. The uncertainty exists because the surface grade in this region is essentially flat. There is a lot of small up and down variations, but overall it is very difficult to determine the general trend, suggesting that when the depression and channels formed the grade was different, and there is no way from this data to determine the angle at that time.

Were the flows that created the channels lava or water or ice? Knowing the grade when these channels formed would help answer this question, but other research now suggests the latter.
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Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on January 1, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a small part of a region dubbed Iani Chaos, but what this geology shows is way beyond my pay grade.

Why there are those tiny aligned mounds, oriented at right angles to the slope, is not clear at all. Nor is it obvious what created the lighter chaotic terrain at the base of the slope.

The elevation difference between the low and high points is about 400 feet. The slope continues up to the west for another 600 feet to the top of a north-south ridgeline. The patterns here suggest vaguely some flows downhill, such as that widening east-to-west gap, but only vaguely.

The look at the overview map only compounds the mystery.
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Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on January 31, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled “Lava Embaying Highlands Ridge”, it shows an alcove along a ridgeline that appears filled with material, in this case solid lava.

If you look closely at the ridgeline, you can see several dark streaks on its southern slopes. These streaks could be one of two unique Martian features that remain unexplained. They could be slope streaks, which occur randomly through the year and fade with time, or recurring slope lineae, which occur seasonally at the same locations. In either case, though the streaks look like avalanches, they don’t change the topography, have no debris piles at their base, and even sometimes flow uphill for short lengths. Though there are a number of theories for their formation, many involving dust, none has been accepted as confirmed.

This location and its lava however are the stars of this picture, for a number of reasons, all revealed by the overview map below.
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