Bottom edge of Martian glacier?
Click for full image.
Today’s cool image, taken on May 25, 2020 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), provides a nice example of the typical foot of an inactive buried glacial flow on Mars. The image to the right, rotated, cropped, and reduced to post here, focuses on the center of the full image. Uphill is to the right. The glacier’s edge runs down the middle left of the photo.
Scientists call this a lobate flow because its shape resembles a lobe, smooth and rounded as it comes down the slope. Located at 38 degrees south latitude to the east of Hellas Basin and just to the north of one of that basin’s major infeeding canyons, Harmakhis Valles, this flow comes down the west side of a large mountain. The overview map below provides the context, with the white rectangle indicating the photo’s location.
The glacier here is not considered active. As planetary scientist Alfred McEwen of the Lunar & Planetary Laboratory in Arizona explained to me in a previous post about glaciers just to the south and east of this image,
These are remnant glaciers. Basically they form like glaciers form. They are not active or if they are they are moving so extremely slowly that effectively they are not active.
And as with the glaciers in that earlier post, the repeating lines in this lobate flow (as shown in the close-up of one section of the above image at full resolution to the right) suggest many repeated flow events, each separated by a period of retreat, with each subsequent flow failing to travel as far down the hill. This in turn suggests that each active period either had less snowfall or lasted a shorter period of time.
The craters in this image add weight to the buried ice glacier hypothesis. The football-stadium-sized crater near the top left appears filled with ice, while the two smaller holes to the right look like each impact hit soft slush that simply melted away as the bolide drilled itself down, leaving no rim. Why there is such a difference between the look of these impacts needs to be explained. The two smaller ones might occurred at the same time, when the condition of the ice was the same, but that’s only a guess.
Higher up the repeated flow events appear to be eroding away, with gaps and depressions between them, which also fits with the belief that these glaciers are presently either inactive or sublimating 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.
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Click for full image.
Today’s cool image, taken on May 25, 2020 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), provides a nice example of the typical foot of an inactive buried glacial flow on Mars. The image to the right, rotated, cropped, and reduced to post here, focuses on the center of the full image. Uphill is to the right. The glacier’s edge runs down the middle left of the photo.
Scientists call this a lobate flow because its shape resembles a lobe, smooth and rounded as it comes down the slope. Located at 38 degrees south latitude to the east of Hellas Basin and just to the north of one of that basin’s major infeeding canyons, Harmakhis Valles, this flow comes down the west side of a large mountain. The overview map below provides the context, with the white rectangle indicating the photo’s location.
The glacier here is not considered active. As planetary scientist Alfred McEwen of the Lunar & Planetary Laboratory in Arizona explained to me in a previous post about glaciers just to the south and east of this image,
These are remnant glaciers. Basically they form like glaciers form. They are not active or if they are they are moving so extremely slowly that effectively they are not active.
And as with the glaciers in that earlier post, the repeating lines in this lobate flow (as shown in the close-up of one section of the above image at full resolution to the right) suggest many repeated flow events, each separated by a period of retreat, with each subsequent flow failing to travel as far down the hill. This in turn suggests that each active period either had less snowfall or lasted a shorter period of time.
The craters in this image add weight to the buried ice glacier hypothesis. The football-stadium-sized crater near the top left appears filled with ice, while the two smaller holes to the right look like each impact hit soft slush that simply melted away as the bolide drilled itself down, leaving no rim. Why there is such a difference between the look of these impacts needs to be explained. The two smaller ones might occurred at the same time, when the condition of the ice was the same, but that’s only a guess.
Higher up the repeated flow events appear to be eroding away, with gaps and depressions between them, which also fits with the belief that these glaciers are presently either inactive or sublimating 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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