Zebra layering in the Martian high southern latitudes
Click for original image.
Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on May 16, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The science team labeled it simple as a “terrain sample,” which usually indicates a picture not taken as part of any specific request or research project, but to fill a gap in the photography schedule in order to maintain the camera’s proper temperature.
When such pictures are necessary, the camera team tries to target the most interesting features that will be below MRO during the required time period. In this case they aimed for a north-facing slope, about 340 feet high, made up of a series of terraced layers, distinguished by the sharply contrasting bright flat benches and very dark cliff-faces.
While the cliffs are dark partly because of the sun is coming from the west, putting them in shadow, it is not entirely the cause. Note how the cliffs on the west side of the mound are also dark, suggesting that the darkness is a fundamental feature of the ground itself.
The white dot on the overview map to the right marks the location, about 400 miles north from Mars’ south pole. While this location is not considered part of the south polar ice cap, the terraced slope does appear to mark the edge of a layered ice/dust plateau, similar to other such plateaus that surround the ice cap, with Promethai Planum the most well known. In the inset you can see that this plateau extends to the south with no obvious end. In wider views it appears to connect to the ice cap directly.
As I noted in 2020,
For some reason Promethei Planum is not considered to be part of the layered ice/dust deposits that comprise most of the southern ice cap. Yet, this plateau clearly has layers, as shown in the image above, is made up of ice, as the Mars Express data suggests, and is covered with dust and debris. Why it is excluded from that layered ice/dust cap is not evident to me.
One could ask the same question about today’s cool image. Since this picture was taken in the spring, the white surfaces are likely water ice covered by the thin mantle of clear dry ice that covers everything above 60 degrees latitude during the winter, and then sublimates away with the coming of spring. This location is at 79 degrees south, and so the dry ice mantle is thus probably just beginning to disappear here, and many of the dark spots are likely places where it has done so. The darkness of the cliffs also suggests that the mantle sublimates away first at these steep locations.
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 the past two weeks has the 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 refuses 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.
Click for original image.
Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on May 16, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The science team labeled it simple as a “terrain sample,” which usually indicates a picture not taken as part of any specific request or research project, but to fill a gap in the photography schedule in order to maintain the camera’s proper temperature.
When such pictures are necessary, the camera team tries to target the most interesting features that will be below MRO during the required time period. In this case they aimed for a north-facing slope, about 340 feet high, made up of a series of terraced layers, distinguished by the sharply contrasting bright flat benches and very dark cliff-faces.
While the cliffs are dark partly because of the sun is coming from the west, putting them in shadow, it is not entirely the cause. Note how the cliffs on the west side of the mound are also dark, suggesting that the darkness is a fundamental feature of the ground itself.
The white dot on the overview map to the right marks the location, about 400 miles north from Mars’ south pole. While this location is not considered part of the south polar ice cap, the terraced slope does appear to mark the edge of a layered ice/dust plateau, similar to other such plateaus that surround the ice cap, with Promethai Planum the most well known. In the inset you can see that this plateau extends to the south with no obvious end. In wider views it appears to connect to the ice cap directly.
As I noted in 2020,
For some reason Promethei Planum is not considered to be part of the layered ice/dust deposits that comprise most of the southern ice cap. Yet, this plateau clearly has layers, as shown in the image above, is made up of ice, as the Mars Express data suggests, and is covered with dust and debris. Why it is excluded from that layered ice/dust cap is not evident to me.
One could ask the same question about today’s cool image. Since this picture was taken in the spring, the white surfaces are likely water ice covered by the thin mantle of clear dry ice that covers everything above 60 degrees latitude during the winter, and then sublimates away with the coming of spring. This location is at 79 degrees south, and so the dry ice mantle is thus probably just beginning to disappear here, and many of the dark spots are likely places where it has done so. The darkness of the cliffs also suggests that the mantle sublimates away first at these steep locations.
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 the past two weeks has the 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 refuses 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.
Readers: the rules for commenting!
No registration is required. I welcome all opinions, even those that strongly criticize my commentary.
However, name-calling and obscenities will not be tolerated. First time offenders who are new to the site will be warned. Second time offenders or first time offenders who have been here awhile will be suspended for a week. After that, I will ban you. Period.
Note also that first time commenters as well as any comment with more than one link will be placed in moderation for my approval. Be patient, I will get to it.