Lacy patterns in the high north of Mars
Cool image time! The photo to the right, cropped, reduced, and rotated so that north is up, was taken on May 12, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the strange lacy patterns seen routinely in the very high northern latitudes surrounding the Martian north pole.
Located in a region of the vast northern lowland plains dubbed Scandia Tholi, such features are apparently common here. From a 2011 geology paper of the region’s geological history:
We find that Scandia Tholi display concentric ridges, rugged peaks, irregular depressions, and moats that suggest uplift and tilting of layered plains material by diapirs and extrusion, erosion, and deflation of viscous, sedimentary slurries as previously suggested. These appear to be long-lived features that both pre-date and post-date impact craters.
The small circular feature near the bottom of the picture appears to be a mesa, and might be a pedestal crater, so old that the surrounding terrain has worn away and left the hardened-by-impact crater as a butte. To its right is a larger circular mesa with its scarp well eroded into hollows. This might also be a pedestal crater, or not.
The white lacy patterns could be frost, either water ice or dry ice. That the white lace tends to favor the north-facing slopes lends support to this guess. The photo was taken in the early spring, so the thin mantle of carbon dioxide that falls to cover the polar region south to sixty degrees latitude is only beginning to sublimate away.
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
Cool image time! The photo to the right, cropped, reduced, and rotated so that north is up, was taken on May 12, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the strange lacy patterns seen routinely in the very high northern latitudes surrounding the Martian north pole.
Located in a region of the vast northern lowland plains dubbed Scandia Tholi, such features are apparently common here. From a 2011 geology paper of the region’s geological history:
We find that Scandia Tholi display concentric ridges, rugged peaks, irregular depressions, and moats that suggest uplift and tilting of layered plains material by diapirs and extrusion, erosion, and deflation of viscous, sedimentary slurries as previously suggested. These appear to be long-lived features that both pre-date and post-date impact craters.
The small circular feature near the bottom of the picture appears to be a mesa, and might be a pedestal crater, so old that the surrounding terrain has worn away and left the hardened-by-impact crater as a butte. To its right is a larger circular mesa with its scarp well eroded into hollows. This might also be a pedestal crater, or not.
The white lacy patterns could be frost, either water ice or dry ice. That the white lace tends to favor the north-facing slopes lends support to this guess. The photo was taken in the early spring, so the thin mantle of carbon dioxide that falls to cover the polar region south to sixty degrees latitude is only beginning to sublimate away.
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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