Martian gullies flowing down to a Martian river of ice
Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on May 16, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).
The scientists label this as “gullies previously identified in the walls of Harmakhis Vallis.” The gullies are obvious, the series of erosion features on the cliff wall. The cliff itself drops about 2,800 feet from the rim to the floor, and also appears to have internal horizontal layers that the gullies cut through.
What causes the gullies? Planetary scientists have a number of theories, none of which appear to explain the gullies everywhere on the Martian surface. They all appear in the mid-latitudes, where the most glaciers on Mars are found, and appear to be related to ice or frost freeze-thaw processes, with some gullies actually very ancient and formed when the planet’s rotational tilt was significantly different.
The white dot on the overview map to the right marks the location, on the north wall of Harmakhis Vallis, a long channel that flows 500 miles down into Hellas Basin, the death valley of the red planet. Harmakhis for most of its length appears to be filled with glacial ice, though it is unclear whether that ice is presently active or stationary. As indicated by the inset, at this point the channel narrows, which means the ice flow would have accelerated at this point, when it was active. That added motion would also be a contributing factor in creating the gullies.
In searching Behind the Black for background information on Harmakhis, I discovered that I featured an MRO image of this exact same cliff back in May 2023, though in that picture the shadows made it difficult to see the gullies. In that cool image I noticed the lack of debris at the bottom of the cliff, suggesting that it was probably carried away by the glacier when it was active. This fact strengthens the hypothesis that both the gullies and glacier are present static and unchanging.
The effort to image this cliff over time tells us that scientists are monitoring these gullies and the glacier for any changes. We will have to wait for their published papers to find out if any motion, as the resolution available here is not sufficient to tell.
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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.
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Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on May 16, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).
The scientists label this as “gullies previously identified in the walls of Harmakhis Vallis.” The gullies are obvious, the series of erosion features on the cliff wall. The cliff itself drops about 2,800 feet from the rim to the floor, and also appears to have internal horizontal layers that the gullies cut through.
What causes the gullies? Planetary scientists have a number of theories, none of which appear to explain the gullies everywhere on the Martian surface. They all appear in the mid-latitudes, where the most glaciers on Mars are found, and appear to be related to ice or frost freeze-thaw processes, with some gullies actually very ancient and formed when the planet’s rotational tilt was significantly different.
The white dot on the overview map to the right marks the location, on the north wall of Harmakhis Vallis, a long channel that flows 500 miles down into Hellas Basin, the death valley of the red planet. Harmakhis for most of its length appears to be filled with glacial ice, though it is unclear whether that ice is presently active or stationary. As indicated by the inset, at this point the channel narrows, which means the ice flow would have accelerated at this point, when it was active. That added motion would also be a contributing factor in creating the gullies.
In searching Behind the Black for background information on Harmakhis, I discovered that I featured an MRO image of this exact same cliff back in May 2023, though in that picture the shadows made it difficult to see the gullies. In that cool image I noticed the lack of debris at the bottom of the cliff, suggesting that it was probably carried away by the glacier when it was active. This fact strengthens the hypothesis that both the gullies and glacier are present static and unchanging.
The effort to image this cliff over time tells us that scientists are monitoring these gullies and the glacier for any changes. We will have to wait for their published papers to find out if any motion, as the resolution available here is not sufficient to tell.
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.
Of interest
https://phys.org/news/2024-08-team-pixel-global-image-dataset.html
I still believe the gullies are caused by wind blown sand. Either blown off from above, or blown back up the hill from below, in a continuous erosion cycle.
It will be interesting to test the hypothesis by comparing these “lower altitude” erosion gullies with “higher altitude” which doesn’t have as much density in the wind to move sand grains.