The source of a Martian glacial canyon 750 miles long
Click for original image.
Cool image time! The picture to the right, cropped, reduced, sharpened, and brightened to post here, was taken on May 1, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).
The scientists label this very simply as a “wall on Ausonia Cavis”. Ausonia Cavis — 31 miles long and 20 miles wide at its widest — is one of the many gigantic sinks found in many places on Mars. This particular cliff wall is about 2,000 feet high, though from rim to floor of the sink is closer to 3,000 feet.
The image was likely taken to get a closer look at those gullies flowing down the cliff wall. Previous research of similar cliff walls in this region has found what appears to be seasonal water frost in such gullies, and this image was likely taken to see if more such frost could be spotted here as well.
The white dot on the overview map to the right marks the location, on the northern wall of Ausonia Cavis. The map also shows that Ausonia is the northernmost source for 750-mile-long canyon dubbed Dao Valles that orbital imagery has shown repeatedly to be filled with what looks like a 750-mile-long glacier. As I noted in 2021:
Though there is evidence that the initial formation of this canyon was related to volcanic activity at its source, the Dao Vallis we see today was shaped neither by a river of lava nor a river of water. Instead, what we see is a river of ice, its channel incised over eons by the slow downward flow of glacier that presently fills it.
The gullies on this cliff face, all beginning about halfway down from the rim, suggest that there may be an underground layer of ice at that level, and as it sublimates away each summer it causes the erosion that forms the gullies. That same ice layer might also be source of the ice that has carved this entire canyon, and presently fills most of its length.
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 print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit.
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
Click for original image.
Cool image time! The picture to the right, cropped, reduced, sharpened, and brightened to post here, was taken on May 1, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).
The scientists label this very simply as a “wall on Ausonia Cavis”. Ausonia Cavis — 31 miles long and 20 miles wide at its widest — is one of the many gigantic sinks found in many places on Mars. This particular cliff wall is about 2,000 feet high, though from rim to floor of the sink is closer to 3,000 feet.
The image was likely taken to get a closer look at those gullies flowing down the cliff wall. Previous research of similar cliff walls in this region has found what appears to be seasonal water frost in such gullies, and this image was likely taken to see if more such frost could be spotted here as well.
The white dot on the overview map to the right marks the location, on the northern wall of Ausonia Cavis. The map also shows that Ausonia is the northernmost source for 750-mile-long canyon dubbed Dao Valles that orbital imagery has shown repeatedly to be filled with what looks like a 750-mile-long glacier. As I noted in 2021:
Though there is evidence that the initial formation of this canyon was related to volcanic activity at its source, the Dao Vallis we see today was shaped neither by a river of lava nor a river of water. Instead, what we see is a river of ice, its channel incised over eons by the slow downward flow of glacier that presently fills it.
The gullies on this cliff face, all beginning about halfway down from the rim, suggest that there may be an underground layer of ice at that level, and as it sublimates away each summer it causes the erosion that forms the gullies. That same ice layer might also be source of the ice that has carved this entire canyon, and presently fills most of its length.
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 print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit. 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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