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.
"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
It has been several months since my last Martian pit update, mostly caused by the lack of new pit images coming down from the high resolution camera on Mars Reconnaissance Orbiter (MRO). I think this lack is not because of a lack of additional pits or caves but instead signals the completion of a first high resolution survey of the known pits so far found on Mars. A full list of all past pit updates can be found at the bottom of this post.
Regardless, the image to the right, cropped to post here, is the only such image in months, taken on April 14, 2020, and shows a small isolated pit in the lava slopes between the giant volcanoes Arsia and Pavonis Mons. In the full photograph you can see how isolated is this pit. To the limits of the image there are no other such features, the terrain a relatively smooth plain with only some small ridges and and a scattering of what seem to be partly obscured or eroded small craters.
The overview below map shows this pit’s relationship to the volcanoes as well as to all other known nearby pits.
The white box indicates this pit’s location. The black boxes are all the other pits documented in earlier posts on Behind the Black. The nearest other pit to the north, highlighted in a post in February 2019, is very similar, a single sudden pit in the middle of a relatively featureless plain.
In fact, most of the pits in this area are alike, isolated pits with no other related features. If they are skylights into lava tubes, those tubes show no expression on the surface, which suggests they are either deep underground or simply don’t exist. The assumption that these pits are skylights into larger cave systems is based on Earth experience. On Mars however volcanic lava flow might express itself in different ways.
To better understand this geology we simply have to enter these pits and explore them.
All Martian pit posts since 2018:
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