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Strange land forms on the flanks of Mars’ Arsia Mons volcano

Strange landforms on the flanks of Arsia Mons
Click for original image. Click here for the context camera image.

Cool image time! The center of the photo to the right was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) on September 5, 2021. For posting here I have rotated, cropped, and reduced it, as well as added to each side the lower resolution context camera image of this region.

The ground slopes downhill to the north. Make sure you click on the image to see the full resolution version. In only a few miles the terrain changes from a mound with small knobs to a smooth area with few knobs to a chaotic area where the larger ridges and knobs are the dominant feature, with hollows and canyons in between.

You should also take a look at the full context camera image. Just to the southeast of the above picture is a large depression that looks like it has been filled with lava, with its western rim covered by that flow. Scientists have taken a lot of high resolution pictures of this depression with MRO, trying to decipher its geology.


The white dot on the overview map to the right shows the location of this photo, on the northwest lower flanks of the giant volcano Arsia Mons. The black dots are all the cool images of pits that I have featured in previous posts on Behind the Black.

This location is in the equatorial regions, so nothing here is likely the result of water ice. Instead, we are looking at the variety of geological shapes the fast moving lava of Mars can take as it covers the ground and solidifies.

As always, something familiar on Earth (lava) behaves on Mars in not quite the same way. We could be looking at the two types of lava that the Hawaiians named pahoehoe for smooth lava and a’a for rough lava, but the scales are different and the Martian lavas are not really the same.

In fact, other than stating these are lava flows that came out of a volcano, it is likely a mistake to think they are the same as Earth lava flows. This is Mars, a different planet with a very different history. We need to recognize that at all times.

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On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.

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  • Jay

    Reminds me of the Snake River Plain. We had an engineer that was also a geologist and he would tell us about how the Snake River Plain was formed. He was not of the opinion that which is called the “Yellowstone Hot Spot” was just an eruption that moved, he believed that a regional extinction level impact poked a hole in the crust, it is moving, and that is what caused the hot spot.

  • Star Bird

    Volcanos on Mars just like their here on Earth do you suppose their the makings of Marvin and K-9 Eludium Q-36 Explosive Space Modulator and water for al those Instant Martians

  • Bob

    Looking at the closeup image I found what appears to be evidence of some recent landslides (mostly) in the chaotic area. Using the scale on the wide area image they will be found, about 3000 ft. from the top and left side of the closeup image, as dark lines down the sides of several ridges. What I find intriguing about the marks is that most point approximately in the same direction.
    I wonder why… Elevation changes, Mars Quakes, Martian Dune Buggy races???

  • Bob: Do a search on BtB for “slope streaks.” Even better, click on those words in my post. My post at that link will explain to you what those dark markings might be, and why avalanches is a poor description of them.

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