Is this the source of the sand for the giant dune sea that surrounds the Martian North Pole?
Circling the north pole of Mars is a gigantic dune field dubbed Olympia Undae, with its densest regions (marked in red on the overview map to the right) estimated to be 700 miles long and covering 120 degrees of longitude.
Where does all the sand come from that created this dune ocean? We now have a rough idea. The arrows on the map to the right indicate the direction of the prevailing winds, as recently determined by scientists studying the orientation of dunes. From this it appears that much of the dust comes from the north polar icecap itself, from its lower layers where dust and ice are cemented together. The prevailing winds, especially in the canyons that cut into the icecap, drive that dust out from the lower layers, where it over eons has piled up in that circular ocean of sand.
The white cross marks the location of today’s cool image, an attempt by scientists to photograph at high resolution one of the sources of this sand, on the edge of the icecap.
Click for original image.
The picture to the right, rotated (so north is up), cropped, reduced, and sharpened to post here, was taken on July 9, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The difference in elevation between the high and low spots is several thousand feet. From elevation data that low spot also appears to be a deep depression, as the ground rises again to the south.
This data suggests that the prevailing winds move south through this canyon to scoop out the sand intermixed with the ice in the icecap’s lower levels, which then over time travels out into Olympia Undae, where the winds can take it either west or east, depending on which side of the wind divide that sand falls.
How long this process takes is presently uncertain, though other research has found that the larger dunes in this ocean of sand are moving, and some as much as thirty feet during the height of each Martian summer.
This process is essentially eating out the inside of the north pole icecap. It also helps explain the specific processes by which over time that cap is slowly shrinking, due to the slow loss of water on Mars.
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Circling the north pole of Mars is a gigantic dune field dubbed Olympia Undae, with its densest regions (marked in red on the overview map to the right) estimated to be 700 miles long and covering 120 degrees of longitude.
Where does all the sand come from that created this dune ocean? We now have a rough idea. The arrows on the map to the right indicate the direction of the prevailing winds, as recently determined by scientists studying the orientation of dunes. From this it appears that much of the dust comes from the north polar icecap itself, from its lower layers where dust and ice are cemented together. The prevailing winds, especially in the canyons that cut into the icecap, drive that dust out from the lower layers, where it over eons has piled up in that circular ocean of sand.
The white cross marks the location of today’s cool image, an attempt by scientists to photograph at high resolution one of the sources of this sand, on the edge of the icecap.
Click for original image.
The picture to the right, rotated (so north is up), cropped, reduced, and sharpened to post here, was taken on July 9, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The difference in elevation between the high and low spots is several thousand feet. From elevation data that low spot also appears to be a deep depression, as the ground rises again to the south.
This data suggests that the prevailing winds move south through this canyon to scoop out the sand intermixed with the ice in the icecap’s lower levels, which then over time travels out into Olympia Undae, where the winds can take it either west or east, depending on which side of the wind divide that sand falls.
How long this process takes is presently uncertain, though other research has found that the larger dunes in this ocean of sand are moving, and some as much as thirty feet during the height of each Martian summer.
This process is essentially eating out the inside of the north pole icecap. It also helps explain the specific processes by which over time that cap is slowly shrinking, due to the slow loss of water on Mars.
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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