A strange dune in the high southern latitudes of Mars
Click for original image.
Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on October 24, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). I have also rotated the image so that north is to the top.
The scientists label this a “dune with seasonally persistent light-toned features.” As the location is in the high southern latitudes, only about 800 miles from the south pole, light-toned features should vary by seasons, as such features usually signal the coming and going of frost, whether it be water ice or dry ice. In this case however the light tones remain from season to season, which suggests the lighter colors are intrinsic to the ground and possibly signal some interesting geology or mineralogy.
The color strip down the center of the dune is an effort to decipher this question. According to the explanation about the colors [pdf] provided by the science team, the orange and light green probably indicates fine dust, while the greenish area along the ridge’s rim as well as its eastern slope suggests frost. Thus, based on the superficial information available to the public, the colors tell us little.
The white dot near the bottom of the overview map to the right marks the location, inside a small and heavily eroded small crater. In the inset, note the very dark and distinct material that surrounds this dune. At this high latitude such patches inside craters are usually light in color, and indicate glacial debris. In this case the dark color instead suggests volcanic ash. Why it should have gathered so distinctly in this one patch however is a mystery. If there was an eruption nearby it would have sprayed ash in many places, not just here.
Ash is only a guess. The dark material might be something else, and also might explain the persistent colors in the dune. Or it might not. It appears from both the image above and the inset that the dark material came after this dune, and simply covers its lower layers. In the high resolution image the material resembles glacial debris, but its dark color in the lower resolution inset remains a puzzle.
The white patches on the slopes of this dune thus remain a puzzle. They suggest some interesting mineralogy, but exactly what cannot be determined by the data on hand.
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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.
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Click for original image.
Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on October 24, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). I have also rotated the image so that north is to the top.
The scientists label this a “dune with seasonally persistent light-toned features.” As the location is in the high southern latitudes, only about 800 miles from the south pole, light-toned features should vary by seasons, as such features usually signal the coming and going of frost, whether it be water ice or dry ice. In this case however the light tones remain from season to season, which suggests the lighter colors are intrinsic to the ground and possibly signal some interesting geology or mineralogy.
The color strip down the center of the dune is an effort to decipher this question. According to the explanation about the colors [pdf] provided by the science team, the orange and light green probably indicates fine dust, while the greenish area along the ridge’s rim as well as its eastern slope suggests frost. Thus, based on the superficial information available to the public, the colors tell us little.
The white dot near the bottom of the overview map to the right marks the location, inside a small and heavily eroded small crater. In the inset, note the very dark and distinct material that surrounds this dune. At this high latitude such patches inside craters are usually light in color, and indicate glacial debris. In this case the dark color instead suggests volcanic ash. Why it should have gathered so distinctly in this one patch however is a mystery. If there was an eruption nearby it would have sprayed ash in many places, not just here.
Ash is only a guess. The dark material might be something else, and also might explain the persistent colors in the dune. Or it might not. It appears from both the image above and the inset that the dark material came after this dune, and simply covers its lower layers. In the high resolution image the material resembles glacial debris, but its dark color in the lower resolution inset remains a puzzle.
The white patches on the slopes of this dune thus remain a puzzle. They suggest some interesting mineralogy, but exactly what cannot be determined by the data on hand.
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.
Just guessing, but the green-ish sands could contain chlorites rich in (iron-aluminium-phyllosilicate) like chamosite, or even glauconite (iron-potassium-phyllosilicate). Mars continues to be a ‘box of chocolates’.