How to spot a glacier on Mars
Click for full image.
The science team for the high resolution camera on Mars Reconnaissance Orbiter (MRO) today posted a nice lesson on what features to look for when you are trying to find glaciers on Mars.
To do this they used one of the earliest images of a Martian glacier, taken by MRO on June 12, 2008. The image to the right, cropped and reduced to post here, shows that entire glacier, coming off a mesa in the chaos terrain region of Protonilus Mensae, a region of mesas and glaciers that I highlighted in an earlier post in December, showing images of a mesa that had numerous glaciers flowing down from all sides.
The overview map to the right shows the location of both that earlier glacier-surrounded mesa (the red dot in Protonilus Mensae) and today’s image (the blue dot).
What the MRO science team has done with the image today however is to use it to illustrate the most important geological features that one will see when looking at a Martian glacier.
One annotated section of the above image points out the foot of the glacier and moraine of material that the glacier had pushed out in front of it as it flowed. A second section focuses on the “linear features resembling fractures, as seen on many terrestrial glaciers,” which also resemble the parallel ridges and grooves that had been highlighted in an earlier MRO image posted only last week.
A third section notes the parallel lines visible along the glaciers edge near the valley walls. As they observe, these layers “could potentially be exposed layers or lines that mark the [glaciers]’s past levels.”
Finally, a fourth section shows the flowing flow features in the plains just beyond the moraine (only partly visible in my cropped image above). These are common near glaciers on Mars, and represent evidence of a time period when the glacier was active, with the ice pushing its way into the flats below the mesa.
This glacier however is likely not active today. Instead it still exists because it is buried by a veneer of dust and debris, that insulates it from the Sun and prevents it from sublimating away. It is probably more than a million years since this glacier moved, during the last time when Mars’ inclination was more than about 30 degrees and as great as 60 degrees. That higher inclination made the poles warmer than the mid-latitudes, thus transferring water from those poles to the mid-latitudes to fall as snow on these glaciers.
Today, with the planet’s inclination at 25 degrees, it is believed (but not proven) that the glaciers and poles of Mars are in a steady state. Some evidence suggests however that any the mid-latitude glaciers exposed to the Sun are shrinking, indicating that the process is reversing, and the ice at the mid-latitudes is beginning to sublimate back to the poles.
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.
The science team for the high resolution camera on Mars Reconnaissance Orbiter (MRO) today posted a nice lesson on what features to look for when you are trying to find glaciers on Mars.
To do this they used one of the earliest images of a Martian glacier, taken by MRO on June 12, 2008. The image to the right, cropped and reduced to post here, shows that entire glacier, coming off a mesa in the chaos terrain region of Protonilus Mensae, a region of mesas and glaciers that I highlighted in an earlier post in December, showing images of a mesa that had numerous glaciers flowing down from all sides.
The overview map to the right shows the location of both that earlier glacier-surrounded mesa (the red dot in Protonilus Mensae) and today’s image (the blue dot).
What the MRO science team has done with the image today however is to use it to illustrate the most important geological features that one will see when looking at a Martian glacier.
One annotated section of the above image points out the foot of the glacier and moraine of material that the glacier had pushed out in front of it as it flowed. A second section focuses on the “linear features resembling fractures, as seen on many terrestrial glaciers,” which also resemble the parallel ridges and grooves that had been highlighted in an earlier MRO image posted only last week.
A third section notes the parallel lines visible along the glaciers edge near the valley walls. As they observe, these layers “could potentially be exposed layers or lines that mark the [glaciers]’s past levels.”
Finally, a fourth section shows the flowing flow features in the plains just beyond the moraine (only partly visible in my cropped image above). These are common near glaciers on Mars, and represent evidence of a time period when the glacier was active, with the ice pushing its way into the flats below the mesa.
This glacier however is likely not active today. Instead it still exists because it is buried by a veneer of dust and debris, that insulates it from the Sun and prevents it from sublimating away. It is probably more than a million years since this glacier moved, during the last time when Mars’ inclination was more than about 30 degrees and as great as 60 degrees. That higher inclination made the poles warmer than the mid-latitudes, thus transferring water from those poles to the mid-latitudes to fall as snow on these glaciers.
Today, with the planet’s inclination at 25 degrees, it is believed (but not proven) that the glaciers and poles of Mars are in a steady state. Some evidence suggests however that any the mid-latitude glaciers exposed to the Sun are shrinking, indicating that the process is reversing, and the ice at the mid-latitudes is beginning to sublimate back to the poles.
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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