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Curiosity takes a close look at a Martian cliff

A cliff of Mars
Click for full resolution. Original images here and here.

Curiosity has now moved up and into Maria Gordon Notch, a gap in the mountains of Gale Crater that is about forty feet wide, with a 40-foot-high cliff on its western side and a 30 to 60 foot cliff on its eastern side.

The mosaic above, created from two navigation camera images, looks up at the top half of that western cliff. Note the many many layers, each one of which records some climate or volcanic event in Mars’ geological history. The Mars we see today took a long time and many events to become what it is. Such layers however have not been seen everywhere by Curiosity. Compare for example this layered cliff with the massive outcrop dubbed Siccar Point and looked at closely by the rover in October. In that outcrop the layers were either non-existent, or merged together during some subsequent geological process.

Note also the pond of sand/dust at the center-bottom, nestled in a hollow but sitting almost vertical. That the dust can maintain itself at such an angle illustrates Mars’ lighter gravity, about 39% of Earth’s, which in turn allows for a much steeper angle of repose. That lighter gravity also allows for some sections of rock to stick out more precariously than possible on Earth.

As Curiosity moves through the notch in the next few days, more such cool pictures will become available, and I shall post them.

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.

 
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"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

5 comments

  • dave b

    larger outcrops of solid rock at lower gravity makes sense. The rock has the same strength, but is under less load.

    However if the slope is of loose (unbonded) grains I do not see where gravity makes much difference. Dry fine grained wind deposits (of glacial rock flour in particular) can have near vertical angles of repose on earth. I believe it has to do with grain shape. More jagged shapes can interlock and stack steeper. At least that’s what I remember from a 1980’s geology field trip.

  • Ken Ffanks

    All the science aside, it looks like many a mesa or ridge I would hike past in the American Southwest. Would love to do some bushwhacking there (I assume LNT rules still apply).

  • Alton

    The Cliff looks like a Gorn should be lurking there somewhere … … …

  • Alton: Same thought. The music from that scene starting running through my head . . .

  • These black and white photos of Martian cliffs look like they could easily be scenes from season one of the original Lost in Space ?

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