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Corroding glacier in crater rim gully?

Gully in crater rim
Click for full image.

Today’s cool image to the right, rotated and cropped to post here, shows a gully flowing down the north facing rim of a 30-mile-wide crater in the southern cratered highlands. It was taken on June 30, 2020 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

To my eye the corroded ridges and pits running down the western side of this gully look like a corroded ice, as if we are looking at a glacier that the light of the Sun, which in the southern hemisphere hits this north-facing slope more directly and for longer periods of time, is causing it to sublimate away with time.

The wider shot below shows the entire rim, flowing downhill from the south to the north.

Wider shot showing entire crater rim

The material above the rim also appears to be glacial, at least superficially, in that the canyon floors all appear to be filled with buried ice, with a general flow downhill towards this particular gully.

All this is a pure guess on my part as a amateur planetary scientist, and should not be taken very seriously. The latitude however, 43 degrees south, lends weight to my suppositions.

Regardless, the gully suggests the potential for seasonal changes from year to year. Unfortunately, scientists have not done this, likely because there are far too many similar good targets on Mars. This image is the first high resolution image taken of this gully by MRO.

The crater itself is located on the western edge of Icaria Planum, a relatively flat plain about 350 miles wide in the southern cratered highlands and located about 1,200 miles south of Arsia Mons and Valles Marineris.

Overview map

The overview map to the right gives the context. The tiny white box on the western edge of Icaria Planum indicates this crater’s location.

This location is also at the southern edge of the Tharsis Bulge, where all of Mars’ biggest volcanoes are located. Thus, what we see here could also be volcanic in nature, or at least shaped initially by lava flows and impact, then overlain by glacial material and windblown sand and dust later.


Conscious Choice cover

Now available in hardback and paperback as well as ebook!


From the press release: In this ground-breaking new history of early America, historian Robert Zimmerman not only exposes the lie behind The New York Times 1619 Project that falsely claims slavery is central to the history of the United States, he also provides profound lessons about the nature of human societies, lessons important for Americans today as well as for all future settlers on Mars and elsewhere in space.

Conscious Choice: The origins of slavery in America and why it matters today and for our future in outer space, is a riveting page-turning story that documents how slavery slowly became pervasive in the southern British colonies of North America, colonies founded by a people and culture that not only did not allow slavery but in every way were hostile to the practice.  
Conscious Choice does more however. In telling the tragic history of the Virginia colony and the rise of slavery there, Zimmerman lays out the proper path for creating healthy societies in places like the Moon and Mars.


“Zimmerman’s ground-breaking history provides every future generation the basic framework for establishing new societies on other worlds. We would be wise to heed what he says.” —Robert Zubrin, founder of founder of the Mars Society.


All editions available at Amazon, Barnes & Noble, and all book vendors. The ebook can be purchased direct from my ebook publisher, ebookit, in which case you don't support the big tech companies and I get a bigger cut much sooner. Note that the price for the ebook, $3.99, goes up to $5.99 on September 1, 2022.


Autographed printed copies are also available at discount directly from me (hardback $24.95; paperback $14.95). Just email me at zimmerman @ nasw dot org.

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