Martian dunes with frost and a sublimating dry ice mantle
Click for original image.
Cool image time! The picture to the right, cropped to post here, was taken on March 16, 2024 by the high resolution camera of Mars Reconnaissance Orbiter (MRO). It was released today as a captioned picture from MRO’s camera team. As noted in the caption, written by the camera’s principal investigator Alfred McEwen:
This image shows a field a sand dunes in the Martian springtime while the seasonal carbon dioxide frost is sublimating into the air. This sublimation process is not at all uniform, instead creating a pattern of dark spots.
In addition, the inter-dune areas are also striking, with bright frost persisting in the troughs of polygons. Our enhanced-color cutout is centered on a brownish-colored inter-dune area.
Each winter the carbon dioxide in the Martian atmosphere falls as snow, mantling the surface in the latitudes above 60 degrees with a clear coat of dry ice. When spring arrives the sunlight passes through the mantle to heat the ground below, which in turn causes the base of the dry ice mantle to sublimate into gas. When the pressure builds enough, the gas breaks through the mantle at its weak points, spewing out and bringing with it dust from below, which stains the mantle with the dark spots.
The black dot in the overview map’s inset to the right marks the location, to the southeast of Argyre Basin. This dune field formed at the base of the north rim of an 35-mile-wide unnamed crater, located in the southern cratered highlands at 61 degrees south latitude.
If you look at the full image instead of the smaller color-enhanced section above, you can see that this section of brown frosted dunes is nestled in an alcove of a field of much larger dunes that gathered at the crater’s interior slope. On these larger dunes the dark splotches are more evident because the frost in the low points is more pronounced.
Most of the rest of the crater’s floor appears covered with a smooth surface impregnated by near surface ice and cross-crossed with dust devil tracks. It also appears that this glacial material has flowed either in or out of the crater through the gap in its southern rim.
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:
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c/o Robert Zimmerman
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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. And if you buy the books through the ebookit links, I get a larger cut and I get it sooner.
Click for original image.
Cool image time! The picture to the right, cropped to post here, was taken on March 16, 2024 by the high resolution camera of Mars Reconnaissance Orbiter (MRO). It was released today as a captioned picture from MRO’s camera team. As noted in the caption, written by the camera’s principal investigator Alfred McEwen:
This image shows a field a sand dunes in the Martian springtime while the seasonal carbon dioxide frost is sublimating into the air. This sublimation process is not at all uniform, instead creating a pattern of dark spots.
In addition, the inter-dune areas are also striking, with bright frost persisting in the troughs of polygons. Our enhanced-color cutout is centered on a brownish-colored inter-dune area.
Each winter the carbon dioxide in the Martian atmosphere falls as snow, mantling the surface in the latitudes above 60 degrees with a clear coat of dry ice. When spring arrives the sunlight passes through the mantle to heat the ground below, which in turn causes the base of the dry ice mantle to sublimate into gas. When the pressure builds enough, the gas breaks through the mantle at its weak points, spewing out and bringing with it dust from below, which stains the mantle with the dark spots.
The black dot in the overview map’s inset to the right marks the location, to the southeast of Argyre Basin. This dune field formed at the base of the north rim of an 35-mile-wide unnamed crater, located in the southern cratered highlands at 61 degrees south latitude.
If you look at the full image instead of the smaller color-enhanced section above, you can see that this section of brown frosted dunes is nestled in an alcove of a field of much larger dunes that gathered at the crater’s interior slope. On these larger dunes the dark splotches are more evident because the frost in the low points is more pronounced.
Most of the rest of the crater’s floor appears covered with a smooth surface impregnated by near surface ice and cross-crossed with dust devil tracks. It also appears that this glacial material has flowed either in or out of the crater through the gap in its southern rim.
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.
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