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More glaciers in Mars’ glacier country

Overview map

glacial layering in Clasia Vallis
Click for full image.

Cool image time! The photo to the right, rotated, cropped, and reduced to post here, was taken on June 18, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what appear to be layered glacial features on the floor of what at first glance appears to be a crater.

It is not a crater however. The depression in the lower right of this image is the rim and floor of a 77-mile-long meandering canyon on Mars dubbed Clasia Vallis. The red cross in the overview map above marks its location, at 34 degrees north latitude. This channel drains downward from the southern cratered highlands into the 2,000-mile-long mid-latitude strip of mensae terrain that I dub glacier country because almost every hi-res image from this region shows glacial features.

Below is a wider view of Clasia Vallis, taken by the context camera on MRO on March 19, 2014.

Context camera view of part of Clasia Vallis
Click for full image.

The white rectangle indicates the area viewed in the close-up above. If you look close you will see that the entire floor of this meandering channel appears to be glacial filled. The picture itself only covers a small part of Clasia Vallis. The full context camera image includes almost all of its upstream drainage, which slowly shrinks until it vanishes into the flat plateau above.

Other context camera images show the canyon grow and eventually drain into the chaos terrain of Nilosyrtis Mensae. In fact, all the canyons in this region, of which there are many, all seem filled with glacial debris on their floor, all flowing downhill to the mensae regions to the east.

The layers in the canyon once again invoke the many climate cycles that seem central to the geology of Mars. With each cycle, the glacier grows and then shrinks, with the overall trend laying down less ice each time.

Genesis cover

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.

The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.

The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.

"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News

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