Sinuous ridge inside Martian canyon
Click for original image.
Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on February 7, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the camera team labels a “sinuous ridge within valley.”
The location is at 30 degrees south latitude, right on the edge of the southern of the two 30-60 degree mid-latitude bands where orbital images show many glacial features. Closer to the equator and there is little or no evidence of near surface ice on Mars. Farther from the equator from this latitude and the evidence of near surface ice increases, becoming very dominant the closer to the poles you get.
At this spot, it appears there is little near surface ice. The channel has ripple sand dunes inside it, and the sinuous ridge appears to be bedrock. Similarly, the plateau above the channel also appears like bedrock, the craters showing no evidence of splatter that is common where there is near surface ice.
What made the channel? And what made that a sinuous ridge inside it?
The white cross north of Hellas Basin on the overview map to the right marks the location of this channel, which appears to be part of a major but unnamed drainage down into Hellas. To the south the canyons Dao, Harmakhis, and Reull all have lots of glacial features within them, and actually appear to be in the process of being carved out by those glaciers, when those presently inactive glaciers have been active in the past.
It is therefore very probable that this channel was carved by glacial activity also in the past, but because of its proximity to the equator that ice is now long gone.
The sinuous ridge suggests the remains of a much earlier channel, created first. Its floor got packed hard so that it became more resistant to erosion. When the larger later glacier carved out the larger channel, it removed the material around this older small channel, leaving behind that sinuous ridge.
At least, that’s my theory, which is also the guess of an amateur.
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.
Click for original image.
Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on February 7, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the camera team labels a “sinuous ridge within valley.”
The location is at 30 degrees south latitude, right on the edge of the southern of the two 30-60 degree mid-latitude bands where orbital images show many glacial features. Closer to the equator and there is little or no evidence of near surface ice on Mars. Farther from the equator from this latitude and the evidence of near surface ice increases, becoming very dominant the closer to the poles you get.
At this spot, it appears there is little near surface ice. The channel has ripple sand dunes inside it, and the sinuous ridge appears to be bedrock. Similarly, the plateau above the channel also appears like bedrock, the craters showing no evidence of splatter that is common where there is near surface ice.
What made the channel? And what made that a sinuous ridge inside it?
The white cross north of Hellas Basin on the overview map to the right marks the location of this channel, which appears to be part of a major but unnamed drainage down into Hellas. To the south the canyons Dao, Harmakhis, and Reull all have lots of glacial features within them, and actually appear to be in the process of being carved out by those glaciers, when those presently inactive glaciers have been active in the past.
It is therefore very probable that this channel was carved by glacial activity also in the past, but because of its proximity to the equator that ice is now long gone.
The sinuous ridge suggests the remains of a much earlier channel, created first. Its floor got packed hard so that it became more resistant to erosion. When the larger later glacier carved out the larger channel, it removed the material around this older small channel, leaving behind that sinuous ridge.
At least, that’s my theory, which is also the guess of an amateur.
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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