Exploring the cratered southern highlands of Mars, part 4
Click for full image.
Today is the last part in our four part exploration of the cratered southern highlands of Mars, begun last week. (For the early parts, go here-Part #1, here-Part #2, and here-Part #3.) Though there is no need, new readers should read the first three parts first, in order to get the larger perspective of this final post.
The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on December 20, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the eastern main gully descending down into a pit that sits in the north center of 52-mile-wide Asimov Crater, as shown in the inset on the overview map above. (For an MRO high resolution of the western gullies into this pit, see this January 2019 cool image post.)
Like Rabe Crater (also shown on the overview map) as well as all the craters around it as well as many near Asimov, the interior floor of Asimov crater is eroding away. Unlike those other craters highlighted in the previous parts of this series, today’s image shows the likely glacial ice nature of that erosion much more clearly. Note the parallel cracks cutting across the slope, all of which suggest that as the gully erodes the ice on its slope is also sagging downward, forming cracks as sections separate under the pressure of gravity. Since this region of the southern cratered highlands is all inside the 30 to 60 degree latitude band where scientists have generally found ample evidence of buried glaciers or ice, such glacier-like features should not surprise us.
Overall, our short survey of the southern cratered highlands suggests that the glacial material and ice found in the southern mid-latitudes affects the Martian surface differently than in the northern lowland plains. In the north the craters and the surrounding terrain often appear blobby, as if the ice is close to the surface and also a dominant component of the ground. Impacts therefore cause significant soft melt features, with craters often heavily distorted. Similarly, there is evidence of the existence of past mud volcanoes that once spewed water and mud from below ground.
In the south however the surface is at a higher elevation, and it appears the ice layer is deeper underground. Thus, it appears the ground is more firm, and the only obvious evidence of an underground layer of ice is revealed when sublimation and the subsequent erosion produce these large pits inside craters.
This very cursory look at Mars very tentatively suggests that future colonists will find it a bit harder to access ice in the southern mid-latitudes, while also finding it easier to build their colonies, since the ground will be firm with solid bedrock.
Readers!
Please consider supporting my work here at Behind the Black. Your support allows me the freedom and ability to analyze objectively the ongoing renaissance in space, as well as the cultural changes -- for good or ill -- that are happening across America. Fourteen years ago I wrote that SLS and Orion were a bad ideas, a waste of money, would be years behind schedule, and better replaced by commercial private enterprise. Only now does it appear that Washington might finally recognize this reality.
In 2020 when the world panicked over COVID I wrote that the panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Only in the past year have some of our so-called experts in the health field have begun to recognize these facts.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
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4. Donate by check, payable to Robert Zimmerman and mailed to
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You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
Click for full image.
Today is the last part in our four part exploration of the cratered southern highlands of Mars, begun last week. (For the early parts, go here-Part #1, here-Part #2, and here-Part #3.) Though there is no need, new readers should read the first three parts first, in order to get the larger perspective of this final post.
The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on December 20, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the eastern main gully descending down into a pit that sits in the north center of 52-mile-wide Asimov Crater, as shown in the inset on the overview map above. (For an MRO high resolution of the western gullies into this pit, see this January 2019 cool image post.)
Like Rabe Crater (also shown on the overview map) as well as all the craters around it as well as many near Asimov, the interior floor of Asimov crater is eroding away. Unlike those other craters highlighted in the previous parts of this series, today’s image shows the likely glacial ice nature of that erosion much more clearly. Note the parallel cracks cutting across the slope, all of which suggest that as the gully erodes the ice on its slope is also sagging downward, forming cracks as sections separate under the pressure of gravity. Since this region of the southern cratered highlands is all inside the 30 to 60 degree latitude band where scientists have generally found ample evidence of buried glaciers or ice, such glacier-like features should not surprise us.
Overall, our short survey of the southern cratered highlands suggests that the glacial material and ice found in the southern mid-latitudes affects the Martian surface differently than in the northern lowland plains. In the north the craters and the surrounding terrain often appear blobby, as if the ice is close to the surface and also a dominant component of the ground. Impacts therefore cause significant soft melt features, with craters often heavily distorted. Similarly, there is evidence of the existence of past mud volcanoes that once spewed water and mud from below ground.
In the south however the surface is at a higher elevation, and it appears the ice layer is deeper underground. Thus, it appears the ground is more firm, and the only obvious evidence of an underground layer of ice is revealed when sublimation and the subsequent erosion produce these large pits inside craters.
This very cursory look at Mars very tentatively suggests that future colonists will find it a bit harder to access ice in the southern mid-latitudes, while also finding it easier to build their colonies, since the ground will be firm with solid bedrock.
Readers!
Please consider supporting my work here at Behind the Black. Your support allows me the freedom and ability to analyze objectively the ongoing renaissance in space, as well as the cultural changes -- for good or ill -- that are happening across America. Fourteen years ago I wrote that SLS and Orion were a bad ideas, a waste of money, would be years behind schedule, and better replaced by commercial private enterprise. Only now does it appear that Washington might finally recognize this reality.
In 2020 when the world panicked over COVID I wrote that the panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Only in the past year have some of our so-called experts in the health field have begun to recognize these facts.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation or subscription:
4. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
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