Endless ripple dunes in Mars’ third largest impact basin
Click for original image.
Cool image time! The picture to the right, cropped to post here, was taken on November 30, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).
The section cropped shows only a small portion of the endless ripple dunes seen in this area. The color strip provides us some interesting other details as well as mysteries. The orange indicates dust on the ridges as well as the higher terrain near the center of the picture. The green in the hollows as well as to the east and west suggests coarser materials that have settled in lower elevations. This supposition is reinforced by the orange area near the bottom of the picture where the ripples have mostly dissipated. This is a high spot, and we appear to be looking at a dusty surface. (This impression is clearer in the full image.)
The latitude is high, 48 degrees south, but as far as I know orbital images have not found a lot of ice evidence in this part of Mars.
The red dot on the overview map to the right marks this location. These ripples are near the center of Argyre Basin, the third largest impact basin on Mars, about a thousand miles wide, 17,000 feet deep, and formed approximately four billion years ago, give or take a half billion years.
These dunes are probably oriented all the same way because of prevailing winds. They are probably so extensive because any Martian dust that falls into Argyre probably gets trapped here. The atmosphere is too weak to blow the dust up and out.
One extra tidbit: If you click on the full image, you can see a very distinct and inexplicable short ridgeline, as sharp as a knife, that pops up for only about 2,000 feet. What caused it to appear here is a mystery, with your guess is as good as mine.
Readers!
Every February I run a fund-raising drive during my birthday month. This year I celebrate my 72nd birthday, and hope and plan to continue writing and posting on Behind the Black for as long as I am able.
I hope my readers will support this effort. As I did in my November fund-raising drive, I am offering autographed copies of my books for large donations. Donate $250 and you can have a choice of the hardback of either Genesis: the Story of Apollo 8 or Conscious Choice: The origins of slavery in America and why it matters today and for our future in outer space. Donate $200 and you can get an autographed paperback copy of either.
Please consider supporting my work here at Behind the Black. My analysis of space, politics, and culture, taken from the perspective of an historian, is almost always on the money and ahead of the game. For example, in 2020 I correctly predicted that the COVID 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. Every one of those 2020 conclusions has turned out right.
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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c/o Robert Zimmerman
P.O.Box 1262
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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 original image.
Cool image time! The picture to the right, cropped to post here, was taken on November 30, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).
The section cropped shows only a small portion of the endless ripple dunes seen in this area. The color strip provides us some interesting other details as well as mysteries. The orange indicates dust on the ridges as well as the higher terrain near the center of the picture. The green in the hollows as well as to the east and west suggests coarser materials that have settled in lower elevations. This supposition is reinforced by the orange area near the bottom of the picture where the ripples have mostly dissipated. This is a high spot, and we appear to be looking at a dusty surface. (This impression is clearer in the full image.)
The latitude is high, 48 degrees south, but as far as I know orbital images have not found a lot of ice evidence in this part of Mars.
The red dot on the overview map to the right marks this location. These ripples are near the center of Argyre Basin, the third largest impact basin on Mars, about a thousand miles wide, 17,000 feet deep, and formed approximately four billion years ago, give or take a half billion years.
These dunes are probably oriented all the same way because of prevailing winds. They are probably so extensive because any Martian dust that falls into Argyre probably gets trapped here. The atmosphere is too weak to blow the dust up and out.
One extra tidbit: If you click on the full image, you can see a very distinct and inexplicable short ridgeline, as sharp as a knife, that pops up for only about 2,000 feet. What caused it to appear here is a mystery, with your guess is as good as mine.
Readers!
Every February I run a fund-raising drive during my birthday month. This year I celebrate my 72nd birthday, and hope and plan to continue writing and posting on Behind the Black for as long as I am able.
I hope my readers will support this effort. As I did in my November fund-raising drive, I am offering autographed copies of my books for large donations. Donate $250 and you can have a choice of the hardback of either Genesis: the Story of Apollo 8 or Conscious Choice: The origins of slavery in America and why it matters today and for our future in outer space. Donate $200 and you can get an autographed paperback copy of either.
Please consider supporting my work here at Behind the Black. My analysis of space, politics, and culture, taken from the perspective of an historian, is almost always on the money and ahead of the game. For example, in 2020 I correctly predicted that the COVID 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. Every one of those 2020 conclusions has turned out right.
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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