Lozenge-shaped hole in Martian crater
Click for full image.
Cool image time! The photo to the right, rotated, cropped, reduced, and enhanced to post here, was taken on June 7, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).
The left image shows what the scientists have dubbed a “lozenge-shaped depression” in the middle of an unnamed 60-mile-wide crater in the southern cratered highlands of Mars. The right image shows the same exact depression, but I have brightened the photo in order to see the details in the shadowed depression.
Though the image is inconclusive, the bottom of the darkest spot in that depression cannot be seen, suggesting it could be an entrance into a larger void below.
Even if there is no voids below, why is this depression here? What caused it? The wider view of MRO’s context camera below might give us a hint.
Click for full image.
The white box indicates the area covered by the photo above. The crater’s north and south rims can be seen at the top and bottom of the photo.
At about 28 degrees south latitude this crater is not expected to show much evidence of ice in its interior, and that generally appears to be the case, based on the visual look of the crater floor. If the crater floor had buried glacial fill, you would expect at this latitude to see more erosion features and some bedrock, as seen by a similar crater at a slightly higher latitude highlighted as a cool image in October 2020. The floor’s smoothness suggests instead that we are looking at bedrock, similar to a different crater floor featured in a cool image in August, 2021.
However, if you look closely at the two interior crater in the crater’s northern quadrant you can see what looks like a splash aprons surrounding each, the kind of apron you see often surrounding craters in the northern mid-latitudes, where there is much evidence of near surface ice.
Such aprons however could instead be impact melt and thus volcanic in nature, not the result of melting ice.
If there is buried ice here at this latitude, it would have to be underground to prevent it from sublimating in the warmer equatorial temperatures. The depression suggests that there might an ice layer below ground, and that it might even be sublimating away to leave cave voids behind. That lozenge-shaped depression on the surface could thus be a sinkhole entrance as well as the outlet in which that gas is escaping.
All guesses on my part. What reinforces my hypothesis to my eye is the look of the other small interior craters close to the depression. Though they do not appear to have aprons, they also appear to have impacted into something somewhat soft, like ice.
If this crater has a subsurface ice layer, it would be the lowest latitude such a thing has been identified, and would strengthen the possibility that future colonists will be able to find mineable underground ice practically anywhere on the Martian surface.
Any papers relating to this depression will likely be published in a year or so. Stay tuned. The data from the Martian orbiters continues to make Mars more and more enticing.
Readers!
Every February I run a fund-raising drive during my birthday month. This year I celebrate my 72nd birthday, and hope and plan to continue writing and posting on Behind the Black for as long as I am able.
I hope my readers will support this effort. As I did in my November fund-raising drive, I am offering autographed copies of my books for large donations. Donate $250 and you can have a choice of the hardback of either Genesis: the Story of Apollo 8 or Conscious Choice: The origins of slavery in America and why it matters today and for our future in outer space. Donate $200 and you can get an autographed paperback copy of either.
Please consider supporting my work here at Behind the Black. 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.
Click for full image.
Cool image time! The photo to the right, rotated, cropped, reduced, and enhanced to post here, was taken on June 7, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).
The left image shows what the scientists have dubbed a “lozenge-shaped depression” in the middle of an unnamed 60-mile-wide crater in the southern cratered highlands of Mars. The right image shows the same exact depression, but I have brightened the photo in order to see the details in the shadowed depression.
Though the image is inconclusive, the bottom of the darkest spot in that depression cannot be seen, suggesting it could be an entrance into a larger void below.
Even if there is no voids below, why is this depression here? What caused it? The wider view of MRO’s context camera below might give us a hint.
Click for full image.
The white box indicates the area covered by the photo above. The crater’s north and south rims can be seen at the top and bottom of the photo.
At about 28 degrees south latitude this crater is not expected to show much evidence of ice in its interior, and that generally appears to be the case, based on the visual look of the crater floor. If the crater floor had buried glacial fill, you would expect at this latitude to see more erosion features and some bedrock, as seen by a similar crater at a slightly higher latitude highlighted as a cool image in October 2020. The floor’s smoothness suggests instead that we are looking at bedrock, similar to a different crater floor featured in a cool image in August, 2021.
However, if you look closely at the two interior crater in the crater’s northern quadrant you can see what looks like a splash aprons surrounding each, the kind of apron you see often surrounding craters in the northern mid-latitudes, where there is much evidence of near surface ice.
Such aprons however could instead be impact melt and thus volcanic in nature, not the result of melting ice.
If there is buried ice here at this latitude, it would have to be underground to prevent it from sublimating in the warmer equatorial temperatures. The depression suggests that there might an ice layer below ground, and that it might even be sublimating away to leave cave voids behind. That lozenge-shaped depression on the surface could thus be a sinkhole entrance as well as the outlet in which that gas is escaping.
All guesses on my part. What reinforces my hypothesis to my eye is the look of the other small interior craters close to the depression. Though they do not appear to have aprons, they also appear to have impacted into something somewhat soft, like ice.
If this crater has a subsurface ice layer, it would be the lowest latitude such a thing has been identified, and would strengthen the possibility that future colonists will be able to find mineable underground ice practically anywhere on the Martian surface.
Any papers relating to this depression will likely be published in a year or so. Stay tuned. The data from the Martian orbiters continues to make Mars more and more enticing.
Readers!
Every February I run a fund-raising drive during my birthday month. This year I celebrate my 72nd birthday, and hope and plan to continue writing and posting on Behind the Black for as long as I am able.
I hope my readers will support this effort. As I did in my November fund-raising drive, I am offering autographed copies of my books for large donations. Donate $250 and you can have a choice of the hardback of either Genesis: the Story of Apollo 8 or Conscious Choice: The origins of slavery in America and why it matters today and for our future in outer space. Donate $200 and you can get an autographed paperback copy of either.
Please consider supporting my work here at Behind the Black. 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.
The crater looks like a dried mud hole and the lozenge (looks like an opened pea-pod to me) looks like a sinkhole. I would love it for Ingenuity to explore that.