Monitoring gullies on Mars for changes
Click for original image.
Cool image time! The picture to the right, cropped, reduced, and enhanced to post here, was taken on June 29, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The scientists label the picture simply as “gully monitoring,” with an apparent goal of looking to see if this gully has changed since MRO took the first high resolution image two years previously. In the interim this terrain went from Martian spring, through summer and winter, and has now returned to spring.
As far as I can tell, no changes are visible, but then I am not using the highest resolution data available. Small changes might be detectable in the highest resolution using good detection software. Overall, the gully drops about 3,000 feet.
The white dot in the overview map above marks the location, on the southwest interior rim of an unnamed 30-mile wide crater. This region in the Martian cratered highlands was featured in a four part cool image series I did back 2023 (here, here, here, and here), with this as my conclusion:
Overall, our short survey of the southern cratered highlands suggests that the glacial material and ice found in the southern mid-latitudes affects the Martian surface differently than in the northern lowland plains. In the north the craters and the surrounding terrain often appear blobby, as if the ice is close to the surface and also a dominant component of the ground. Impacts therefore cause significant soft melt features, with craters often heavily distorted. Similarly, there is evidence of the existence of past mud volcanoes that once spewed water and mud from below ground.
In the south however the surface is at a higher elevation, and it appears the ice layer is deeper underground. Thus, it appears the ground is more firm, and the only obvious evidence of an underground layer of ice is revealed when sublimation and the subsequent erosion produce these large pits inside craters.
In the case of this crater, a small impact on its interior southwest slope apparently caused that underground layer of ice to melt temporarily and flow downhill, leaving behind the gully and flow features we see today. Based on the two MRO pictures taken a full Martian year apart, it appears the feature is generally stable and thus likely old, left over from that impact. If things are changing seasonally they are doing so in small amounts and slowly.
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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.
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.
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Click for original image.
Cool image time! The picture to the right, cropped, reduced, and enhanced to post here, was taken on June 29, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The scientists label the picture simply as “gully monitoring,” with an apparent goal of looking to see if this gully has changed since MRO took the first high resolution image two years previously. In the interim this terrain went from Martian spring, through summer and winter, and has now returned to spring.
As far as I can tell, no changes are visible, but then I am not using the highest resolution data available. Small changes might be detectable in the highest resolution using good detection software. Overall, the gully drops about 3,000 feet.
The white dot in the overview map above marks the location, on the southwest interior rim of an unnamed 30-mile wide crater. This region in the Martian cratered highlands was featured in a four part cool image series I did back 2023 (here, here, here, and here), with this as my conclusion:
Overall, our short survey of the southern cratered highlands suggests that the glacial material and ice found in the southern mid-latitudes affects the Martian surface differently than in the northern lowland plains. In the north the craters and the surrounding terrain often appear blobby, as if the ice is close to the surface and also a dominant component of the ground. Impacts therefore cause significant soft melt features, with craters often heavily distorted. Similarly, there is evidence of the existence of past mud volcanoes that once spewed water and mud from below ground.
In the south however the surface is at a higher elevation, and it appears the ice layer is deeper underground. Thus, it appears the ground is more firm, and the only obvious evidence of an underground layer of ice is revealed when sublimation and the subsequent erosion produce these large pits inside craters.
In the case of this crater, a small impact on its interior southwest slope apparently caused that underground layer of ice to melt temporarily and flow downhill, leaving behind the gully and flow features we see today. Based on the two MRO pictures taken a full Martian year apart, it appears the feature is generally stable and thus likely old, left over from that impact. If things are changing seasonally they are doing so in small amounts and slowly.
Readers!
Please consider supporting my work here at Behind the Black. Your support allows 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. 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. Only now does it appear that Washington might finally 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.
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 gully drops about 3,000 feet.
You use this word “gully”. I don’t think it means what you think it means.
For reference, the Grand Canyon averages about twice that. (I looked it up, but an AI answered, so who really knows?)
Mark Sizer: the distance was merely to give a sense of scale. The crater rim itself drops more than 5,000 feet, which is comparable to the hike down from the South Rim of the Grand Canyon.
As for the word “gully,” this is the word the planetary scientists use for these Martian features. They appear to be erosion features, but their origin is not yet completely explained or understood, and might be from many different causes, dependent on latitude, elevation, and the direction the slope faces relative to the Sun.