An ancient Martian river system now meandering ridges
Click for original image.
Cool image time! The picture to the right, cropped and reduced to post here, was taken on August 27, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It was featured by MRO’s science team yesterday, in which Shane Byrne of the Lunar and Planetary Lab University of Arizona wrote the following:
River beds often get filled with gravel and the surrounding terrain is often built up of fine-grained mud from river overflows. The gravely river bottom and the fine-grained surroundings can lead to a strange phenomenon that geologists call inverted channels. After the river disappears, the fine-grained surroundings can be easily eroded away leaving the gravely river bed as a high-standing ridge.
These ridges show the location of the old river beds in Mars’ distant past. The angle at which the ridges join together indicate that these rivers flowed from top-right to bottom-left (i.e. southwest).
The picture above is a mosaic produced from the global survey taken by MRO’s lower resolution context camera. It gives us a fuller picture of this river system, with the rectangle showing the small area covered by the photo on the right. Overall this ancient and extinct river of ridges travels more than thirty miles downhill from the northeast to the southwest.
The white dot on the overview map to the right marks this location, inside the Medusa Fossae Formation, the largest volcanic ash deposit on Mars. The many parallel north-south ridges that the river system cuts across are likely ancient dunes of this volcanic dust, now solidified and being worn away. Whether the ash fell first, then the river flowed through it, or the river was created, turned into ridges, and then the ash followed, is not obvious from the visibile data. All we can see with certainty is the terrain looks old and corruded, with few craters.
We are looking at a window into the far Martian past, uncovered by erosion caused by the endless winds of Mars, weak as they are.
The support of my readers through the years has given 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. Four years ago, just before the 2020 election I wrote that Joe Biden's mental health was suspect. Only in this year has the propaganda mainstream media decided to recognize that basic fact.
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. Even today NASA and Congress refuse to 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.
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Click for original image.
Cool image time! The picture to the right, cropped and reduced to post here, was taken on August 27, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It was featured by MRO’s science team yesterday, in which Shane Byrne of the Lunar and Planetary Lab University of Arizona wrote the following:
River beds often get filled with gravel and the surrounding terrain is often built up of fine-grained mud from river overflows. The gravely river bottom and the fine-grained surroundings can lead to a strange phenomenon that geologists call inverted channels. After the river disappears, the fine-grained surroundings can be easily eroded away leaving the gravely river bed as a high-standing ridge.
These ridges show the location of the old river beds in Mars’ distant past. The angle at which the ridges join together indicate that these rivers flowed from top-right to bottom-left (i.e. southwest).
The picture above is a mosaic produced from the global survey taken by MRO’s lower resolution context camera. It gives us a fuller picture of this river system, with the rectangle showing the small area covered by the photo on the right. Overall this ancient and extinct river of ridges travels more than thirty miles downhill from the northeast to the southwest.
The white dot on the overview map to the right marks this location, inside the Medusa Fossae Formation, the largest volcanic ash deposit on Mars. The many parallel north-south ridges that the river system cuts across are likely ancient dunes of this volcanic dust, now solidified and being worn away. Whether the ash fell first, then the river flowed through it, or the river was created, turned into ridges, and then the ash followed, is not obvious from the visibile data. All we can see with certainty is the terrain looks old and corruded, with few craters.
We are looking at a window into the far Martian past, uncovered by erosion caused by the endless winds of Mars, weak as they are.
The support of my readers through the years has given 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. Four years ago, just before the 2020 election I wrote that Joe Biden's mental health was suspect. Only in this year has the propaganda mainstream media decided to recognize that basic fact.
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. Even today NASA and Congress refuse to 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.
Please consider supporting my work here at Behind the Black.
You can support me either by giving a one-time contribution or a regular subscription. There are five 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:
5. 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. And if you buy the books through the ebookit links, I get a larger cut and I get it sooner.
Inverted channels are nice, but I prefer incised meanders.