Sublimating ice in the Martian dry tropics?
Click for original image.
Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on May 3, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled merely as a “terrain sample,” it was likely snapped not as part of any specific research project but to fill a gap in the camera’s schedule so as to maintain the camera’s proper temperature.
When the MRO camera team does this, they try to pick features of interest at the time required, and I think succeed more often than not. In this case, they captured this one-mile-wide unnamed crater that appears to be filled with sublimating glacial debris. Similarly, the plateau surrounding the crater seems to also show signs that some sublimation is occurring of ice just below the surface, producing the areas that appear filled with pockmarks.
The location however suggests that if near surface ice here is sublimating away, it hints at a find of some significance.
The white dot on the overview map to the right marks the location, well inside the dry Martian tropics at 28 degrees north latitude, and about 500 miles south of the 2,000-mile-long mid-latitude region I dub glacier country because practically every image shows extensive glacial features.
Based on almost all orbital data, there should be no near surface ice at this latitude.
Yet the picture above as well as the inset on the overview map suggests otherwise. The inset shows that this crater is on a plateau with a number of similar craters as well as a meandering tributary canyon system that drains into a lower valley about eighteen miles away.
All the features suggest that there might be a layer of underground ice here, even though it is in Mars’ dry equatorial tropics. And if that ice is gone, the geology suggests there was once a lot, and it once flowed downhill in those canyons to the valley.
Was the flow liquid water or glacial ice? That remains the $64,000 scientific question. And is there still near surface ice at this low latitude? That’s another $64,000 question.
Readers!
My annual February birthday fund-raising drive for Behind the Black is now over. Thank you to everyone who donated or subscribed. While not a record-setter, the donations were more than sufficient and slightly above average.
As I have said many times before, I can’t express what it means to me to get such support, especially as no one is required to pay anything to read my work. Thank you all again!
For those readers who like my work here at Behind the Black and haven't contributed so far, please consider donating or subscribing. 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
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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.
Click for original image.
Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on May 3, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled merely as a “terrain sample,” it was likely snapped not as part of any specific research project but to fill a gap in the camera’s schedule so as to maintain the camera’s proper temperature.
When the MRO camera team does this, they try to pick features of interest at the time required, and I think succeed more often than not. In this case, they captured this one-mile-wide unnamed crater that appears to be filled with sublimating glacial debris. Similarly, the plateau surrounding the crater seems to also show signs that some sublimation is occurring of ice just below the surface, producing the areas that appear filled with pockmarks.
The location however suggests that if near surface ice here is sublimating away, it hints at a find of some significance.
The white dot on the overview map to the right marks the location, well inside the dry Martian tropics at 28 degrees north latitude, and about 500 miles south of the 2,000-mile-long mid-latitude region I dub glacier country because practically every image shows extensive glacial features.
Based on almost all orbital data, there should be no near surface ice at this latitude.
Yet the picture above as well as the inset on the overview map suggests otherwise. The inset shows that this crater is on a plateau with a number of similar craters as well as a meandering tributary canyon system that drains into a lower valley about eighteen miles away.
All the features suggest that there might be a layer of underground ice here, even though it is in Mars’ dry equatorial tropics. And if that ice is gone, the geology suggests there was once a lot, and it once flowed downhill in those canyons to the valley.
Was the flow liquid water or glacial ice? That remains the $64,000 scientific question. And is there still near surface ice at this low latitude? That’s another $64,000 question.
Readers!
My annual February birthday fund-raising drive for Behind the Black is now over. Thank you to everyone who donated or subscribed. While not a record-setter, the donations were more than sufficient and slightly above average.
As I have said many times before, I can’t express what it means to me to get such support, especially as no one is required to pay anything to read my work. Thank you all again!
For those readers who like my work here at Behind the Black and haven't contributed so far, please consider donating or subscribing. 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.
My guess for what caused the crater – a 1-mile diameter wadcutter round, made of water-ice. At the time of impact, there was a local-system ban on the use of heavy-metals for large-caliber shooting, hence water was next up. You know how effective test-ban treaties are on earth. Who knew even aliens have their quirks! Makes for an interesting pix though.