Ice-filled crater on the Martian north polar ice cap
Click for full image.
Cool image time! The photo to the right, cropped to post here, was taken on September 18, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO) and shows a very distinct impact crater on top of the layered deposits of ice mixed with dirt that form the bottom layers as well as surround the visible north pole ice cap on Mars.
I purposely cropped the high resolution image so that the crater is off center to show the dark streaks that appear to blow away from the crater to the northwest, west, and southwest. This asymmetric pattern suggests the wind direction at this location generally flows to the west, but the pattern might also be caused by lighting effects. The location is at 82 degrees north latitude, and the Sun was only 31 degrees high when the picture was taken, causing long shadows. Also, in the full image, you can see a whole strip of similarly oriented streaks, suggesting that these are slope streaks descending a slope going downhill to the northwest.
The overview map below also provides important information about this location.
The yellow cross indicates the location of this small 500-foot-wide crater. For most of the ice cap, the descent down from the icy upper layers (generally green on the map) to the dirtier layered deposits (trending to blue on the map) is steep and abrupt, a cliff where orbital images routinely capture avalanches in the spring, as they occur. At this location however that slope going down to the west is more gentle, with only a few relatively small and gentle steps downward. This crater happens to be located along one of those steps, which might explain the northwest pointing streaks.
Note that the ice in the crater might not be water ice. At this latitude each winter a mantle of dry ice snow covers everything, only to sublimate away when the Sun arrives in the spring. It is possible that this ice is dry ice that has not yet disappeared.
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.
Click for full image.
Cool image time! The photo to the right, cropped to post here, was taken on September 18, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO) and shows a very distinct impact crater on top of the layered deposits of ice mixed with dirt that form the bottom layers as well as surround the visible north pole ice cap on Mars.
I purposely cropped the high resolution image so that the crater is off center to show the dark streaks that appear to blow away from the crater to the northwest, west, and southwest. This asymmetric pattern suggests the wind direction at this location generally flows to the west, but the pattern might also be caused by lighting effects. The location is at 82 degrees north latitude, and the Sun was only 31 degrees high when the picture was taken, causing long shadows. Also, in the full image, you can see a whole strip of similarly oriented streaks, suggesting that these are slope streaks descending a slope going downhill to the northwest.
The overview map below also provides important information about this location.
The yellow cross indicates the location of this small 500-foot-wide crater. For most of the ice cap, the descent down from the icy upper layers (generally green on the map) to the dirtier layered deposits (trending to blue on the map) is steep and abrupt, a cliff where orbital images routinely capture avalanches in the spring, as they occur. At this location however that slope going down to the west is more gentle, with only a few relatively small and gentle steps downward. This crater happens to be located along one of those steps, which might explain the northwest pointing streaks.
Note that the ice in the crater might not be water ice. At this latitude each winter a mantle of dry ice snow covers everything, only to sublimate away when the Sun arrives in the spring. It is possible that this ice is dry ice that has not yet disappeared.
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 teenagers’ comment:
Mars has a pimple! (been a long day, had to share the humor)