A ridge that runs right over a Martian mesa
Click for original image.
Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on April 5, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). I have cropped it to focus on the geological feature that likely attracted the interest of the scientists who requested this photo, the mesa that has a ridgeline running over it as if the mesa was not even there.
The mesa is about 80 feet high on its west side, but on its east the ground continues to drop away more than 500 feet as you move 2.5 miles to the east. Based on how the MRO science team interprets the colors [pdf] in the color strip, the orange areas are likely dust while the greenish surface suggests coarser sand and boulders. This conclusion is reinforced if you look at the parallel dunes south of the mesa. The dunes are yellow-orange (dust) while the ground between is yellow-green (sand), exactly what you expect with the larger coarser material settling in lower elevations.
The overview map provides the context, which might help explain the ridgeline.
The white dot on the overview map to the right marks the location, with the small rectangle in the inset indicating the area covered by the picture above. The inset shows the surrounding terrain, and is anotated to give some elevation perspective. The low point to the east of the mesa is noted, while the dotted circle indicates the rim of this roughly ten-mile-wide depression, inside a much larger basin about 70 miles in diameter.
This region is filled with many parallel fissures running northeast-to-southwest and illustrated most by the two Nili Fossae fissures. It is also a region known for having a lot of interesting minerals, which is one reason why the scientists chose to land Perseverance in Jezero Crater to the east. The hope is to send the rover west beyond the crater rim into this mineral-rich region to get some data.
The fissures or cracks are thought to have been created by the giant impact about four billion years ago that formed Isidis Basin to the east. The ridge, which also runs northeast-to-southeast, is probably another crack that was later filled with lava, forming what geologists call a dike, made of more resistent material that became a ridge as the surrounding terrain eroded away. As the ground disappeared around the mesa, the ridge became evident.
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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:
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Click for original image.
Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on April 5, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). I have cropped it to focus on the geological feature that likely attracted the interest of the scientists who requested this photo, the mesa that has a ridgeline running over it as if the mesa was not even there.
The mesa is about 80 feet high on its west side, but on its east the ground continues to drop away more than 500 feet as you move 2.5 miles to the east. Based on how the MRO science team interprets the colors [pdf] in the color strip, the orange areas are likely dust while the greenish surface suggests coarser sand and boulders. This conclusion is reinforced if you look at the parallel dunes south of the mesa. The dunes are yellow-orange (dust) while the ground between is yellow-green (sand), exactly what you expect with the larger coarser material settling in lower elevations.
The overview map provides the context, which might help explain the ridgeline.
The white dot on the overview map to the right marks the location, with the small rectangle in the inset indicating the area covered by the picture above. The inset shows the surrounding terrain, and is anotated to give some elevation perspective. The low point to the east of the mesa is noted, while the dotted circle indicates the rim of this roughly ten-mile-wide depression, inside a much larger basin about 70 miles in diameter.
This region is filled with many parallel fissures running northeast-to-southwest and illustrated most by the two Nili Fossae fissures. It is also a region known for having a lot of interesting minerals, which is one reason why the scientists chose to land Perseverance in Jezero Crater to the east. The hope is to send the rover west beyond the crater rim into this mineral-rich region to get some data.
The fissures or cracks are thought to have been created by the giant impact about four billion years ago that formed Isidis Basin to the east. The ridge, which also runs northeast-to-southeast, is probably another crack that was later filled with lava, forming what geologists call a dike, made of more resistent material that became a ridge as the surrounding terrain eroded away. As the ground disappeared around the mesa, the ridge became evident.
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.
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