Baffling ridges on Mars
Click for full image.
Today’s cool image is one of my “what the heck?” photos. The picture to the right, cropped and reduced to post here and taken on September 3, 2020 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), shows a strange dune field of many parallel long dunes, cross-cut by larger ridges.
Are the larger ridges dunes? Or are they some form of volcanic or tectonic ridge, which is also very typical of this region, called Tempe Terra and located in the transition zone between the southern cratered highlands and the northern lowland plains?
Or are they eskers, ridges frequently found in places that were once covered by glaciers? At 35 degrees north latitude, it would not be surprising to see glacial features here, but as far as I can tell, the full image has no obvious such features.
Based on this paper as well as a quick review of the literature, it appears that scientists tend to favor tectonic or volcanic processes for forming the larger fissures and ridges in Terra Tempe.
However, the ridges in the photograph are relatively tiny compared to the many-mile-wide tectonic wrinkle ridges often found in Terra Tempe. These small ridges are also only found in patches, generally flat low areas filled with dust and dunes. In the full image most of the terrain does not have such small ridges, and is instead covered with a rough eroded plateau interspersed with craters and depressions.
That these small ridges are only found in the flat smooth dust- and dune-filled patches is another puzzle.
Maybe they are dikes, extrusions of lava through cracks. Once again, however, why would these cracks be only found in such distinct patches?
It is unlikely (but not impossible) that these ridges are dunes, since we can see the smaller dunes climbing up their slopes, suggesting the ridges are older and more solid. While they are thus likely older bedrock, such as dikes, they could also be older larger dunes that have since solidified into rock. That the ridges do not align (as dunes would generally do because of the prevailing winds) however argues against a dune origin.
So, what do you think? Guessing by everyone is allowed, though it does pay to do some research and learn some basics about geology first so that your guesses are a bit more than mere hand-waving.
But only a bit more. And always remember, you are guessing, as are the scientists (though with greater knowledge). Until we can walk this ground all our theories about its geology are uncertain, and should not be taken on faith without some skepticism.
The support of my readers through the years has given 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. Four years ago, just before the 2020 election I wrote that Joe Biden's mental health was suspect. Only in this year has the propaganda mainstream media decided to recognize that basic fact.
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. Even today NASA and Congress refuse to 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.
Please consider supporting my work here at Behind the Black.
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Click for full image.
Today’s cool image is one of my “what the heck?” photos. The picture to the right, cropped and reduced to post here and taken on September 3, 2020 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), shows a strange dune field of many parallel long dunes, cross-cut by larger ridges.
Are the larger ridges dunes? Or are they some form of volcanic or tectonic ridge, which is also very typical of this region, called Tempe Terra and located in the transition zone between the southern cratered highlands and the northern lowland plains?
Or are they eskers, ridges frequently found in places that were once covered by glaciers? At 35 degrees north latitude, it would not be surprising to see glacial features here, but as far as I can tell, the full image has no obvious such features.
Based on this paper as well as a quick review of the literature, it appears that scientists tend to favor tectonic or volcanic processes for forming the larger fissures and ridges in Terra Tempe.
However, the ridges in the photograph are relatively tiny compared to the many-mile-wide tectonic wrinkle ridges often found in Terra Tempe. These small ridges are also only found in patches, generally flat low areas filled with dust and dunes. In the full image most of the terrain does not have such small ridges, and is instead covered with a rough eroded plateau interspersed with craters and depressions.
That these small ridges are only found in the flat smooth dust- and dune-filled patches is another puzzle.
Maybe they are dikes, extrusions of lava through cracks. Once again, however, why would these cracks be only found in such distinct patches?
It is unlikely (but not impossible) that these ridges are dunes, since we can see the smaller dunes climbing up their slopes, suggesting the ridges are older and more solid. While they are thus likely older bedrock, such as dikes, they could also be older larger dunes that have since solidified into rock. That the ridges do not align (as dunes would generally do because of the prevailing winds) however argues against a dune origin.
So, what do you think? Guessing by everyone is allowed, though it does pay to do some research and learn some basics about geology first so that your guesses are a bit more than mere hand-waving.
But only a bit more. And always remember, you are guessing, as are the scientists (though with greater knowledge). Until we can walk this ground all our theories about its geology are uncertain, and should not be taken on faith without some skepticism.
The support of my readers through the years has given 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. Four years ago, just before the 2020 election I wrote that Joe Biden's mental health was suspect. Only in this year has the propaganda mainstream media decided to recognize that basic fact.
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. Even today NASA and Congress refuse to 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.
Please consider supporting my work here at Behind the Black.
You can support me either by giving a one-time contribution or a regular subscription. There are five 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:
5. 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. And if you buy the books through the ebookit links, I get a larger cut and I get it sooner.
My Guess is that water arrived by way of comet or wayward ice planet. The water soaked the dust and caused the the dust to expand. The ridges are expansion ridges.
Bob,
For a “what the heck?” I would have shown the ‘eyeball’ at the top of the full picture.
Chris: It’s just a crater with a shadow. I think you are perceiving it reversed (which happens sometimes), as a hill.
Hi Bob,
It was just the overall effect of the appearance of the eye and the line of whatever it is from the “pupil” that made me say “what the heck”