Craters in the soft Martian northern lowland plains
Click for full image.
Cool image time! The photo to the right, cropped and reduced to post here, was a featured image today from the high resolution camera on Mars Reconnaissance Orbiter (MRO).
The caption, written by Carol Weitz of the Planetary Science Institute in Arizona, focused on the wind patterns created within these craters.
These impact craters in the northern middle latitudes have interesting interiors: all of them have wind-blown (aeolian) ripples.
Outside of the craters and along the crater floors, the ripples are all oriented in the same direction. However, along the walls of some of the larger craters, the ripples are situated radially away from the center, indicating the winds moving inside the larger craters can be influenced by the topography of the crater wall.
Additionally, many of the larger craters have layered mesas along their floors that are likely sedimentary deposits laid down after the craters formed but prior to the development of the aeolian ripples.
I am further intrigued by the rimless nature of these craters, as well as the lack of significant rocky debris at their edges. They all look like the bolides that created them impacted into a relatively soft surface that, rather than break up into rocks and boulders, melted, flowed, and then quickly refroze into these depressions.
The location, as always, provides us a possible explanation.
The white cross indicates the location of these craters, in an area just north of the region of chaos terrain dubbed Nilosyrtis Mensae, the easternmost part of that 2,000 mile long mid-latitude strip of chaos I dub glacier country because every image taken of the landscape there seems to exhibit glacial features.
Thus, it is very likely that there is a lot of ice very close to the surface at this location. In fact, that ice layer could be dominant, and its presence could easily explain the nature of these craters.
Obviously, that can’t be the whole story. We don’t know how long ago these impacts occurred, and in the interim erosion processes could have reshaped things by quite a lot. Moreover, the data is still somewhat sparse.
Below is a global map of Mars, indicating where scientists have found a lot of evidence of ice. The two lines at 30 degrees latitude indicate the range of detected persistent ice, near the surface. The equatorial regions have so far been found to be dry, though underground ice might still exist.
The regions outlined in white are those where extensive glacial and ice features have been detected as well. For the full resolution version click on the map.
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
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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.
Cool image time! The photo to the right, cropped and reduced to post here, was a featured image today from the high resolution camera on Mars Reconnaissance Orbiter (MRO).
The caption, written by Carol Weitz of the Planetary Science Institute in Arizona, focused on the wind patterns created within these craters.
These impact craters in the northern middle latitudes have interesting interiors: all of them have wind-blown (aeolian) ripples.
Outside of the craters and along the crater floors, the ripples are all oriented in the same direction. However, along the walls of some of the larger craters, the ripples are situated radially away from the center, indicating the winds moving inside the larger craters can be influenced by the topography of the crater wall.
Additionally, many of the larger craters have layered mesas along their floors that are likely sedimentary deposits laid down after the craters formed but prior to the development of the aeolian ripples.
I am further intrigued by the rimless nature of these craters, as well as the lack of significant rocky debris at their edges. They all look like the bolides that created them impacted into a relatively soft surface that, rather than break up into rocks and boulders, melted, flowed, and then quickly refroze into these depressions.
The location, as always, provides us a possible explanation.
The white cross indicates the location of these craters, in an area just north of the region of chaos terrain dubbed Nilosyrtis Mensae, the easternmost part of that 2,000 mile long mid-latitude strip of chaos I dub glacier country because every image taken of the landscape there seems to exhibit glacial features.
Thus, it is very likely that there is a lot of ice very close to the surface at this location. In fact, that ice layer could be dominant, and its presence could easily explain the nature of these craters.
Obviously, that can’t be the whole story. We don’t know how long ago these impacts occurred, and in the interim erosion processes could have reshaped things by quite a lot. Moreover, the data is still somewhat sparse.
Below is a global map of Mars, indicating where scientists have found a lot of evidence of ice. The two lines at 30 degrees latitude indicate the range of detected persistent ice, near the surface. The equatorial regions have so far been found to be dry, though underground ice might still exist.
The regions outlined in white are those where extensive glacial and ice features have been detected as well. For the full resolution version click on the map.
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.
If you had not indicated they were impact “Craters”, I would guess something similar to the mounds in the arctic where ice has been a factor in the uplift.
Agreed the edges don’t have an ejecta rim. The craters also don’t seem to have a central peak – interior topography covered by eolian debris, or not there in the first place?