Mesa in the Martian northern lowlands
Click for full image.
Cool image time! The photo to the right, cropped and reduced to post here, was taken on February 2, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO) and shows a mesa sticking up on the relatively flat and featureless northern lowland plains in Utopia Planitia, the second largest impact basin on Mars.
The full image shows three such mesas. Though pictures taken in the northern lowlands of Utopia tend to show evidence of buried ice or glaciers, the impression I get from this picture is one of dryness. If there is any ice here, it is below ground. And even that seems unlikely. The surface surrounding nearby craters does not have that squishy and slushy look that is seen in the north when an impact occurred on near surface ice. Instead, the ground looks solid.
The overview map below reinforces this impression.
The red dot on the 30th parallel north of Isidis Basin marks the location of this mesa. At that latitude the mesa is at the very southern edge of the 30-60 degree mid-latitude bands where scientists have found many Martian glaciers. While a few spots south of that latitude have been identified where there might be ice, they are few and also uncertain. The general trend is dryness once one gets to 30 degrees.
These mesas are intriguing because they suggest that the surface here was once higher, and that a significant amount of material has been removed over the eons, with these mesas somehow surviving. This hypothesis is strengthened by what look like two pedestal craters just to the east of the mesa. Pedestal craters are thought to be impact spots that resist erosion because the impact smashes the material at the site and makes it more resistant to erosion. When the surrounding terrain erodes away, the crater remains.
What swept those top layers away? A first guess is that once there was underground ice here, and with its slow loss over time the surface dropped away.
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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Click for full image.
Cool image time! The photo to the right, cropped and reduced to post here, was taken on February 2, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO) and shows a mesa sticking up on the relatively flat and featureless northern lowland plains in Utopia Planitia, the second largest impact basin on Mars.
The full image shows three such mesas. Though pictures taken in the northern lowlands of Utopia tend to show evidence of buried ice or glaciers, the impression I get from this picture is one of dryness. If there is any ice here, it is below ground. And even that seems unlikely. The surface surrounding nearby craters does not have that squishy and slushy look that is seen in the north when an impact occurred on near surface ice. Instead, the ground looks solid.
The overview map below reinforces this impression.
The red dot on the 30th parallel north of Isidis Basin marks the location of this mesa. At that latitude the mesa is at the very southern edge of the 30-60 degree mid-latitude bands where scientists have found many Martian glaciers. While a few spots south of that latitude have been identified where there might be ice, they are few and also uncertain. The general trend is dryness once one gets to 30 degrees.
These mesas are intriguing because they suggest that the surface here was once higher, and that a significant amount of material has been removed over the eons, with these mesas somehow surviving. This hypothesis is strengthened by what look like two pedestal craters just to the east of the mesa. Pedestal craters are thought to be impact spots that resist erosion because the impact smashes the material at the site and makes it more resistant to erosion. When the surrounding terrain erodes away, the crater remains.
What swept those top layers away? A first guess is that once there was underground ice here, and with its slow loss over time the surface dropped away.
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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