A Martian cliff
Many features on Mars immediately make one think of the Grand Canyon and the stark dramatic geology of the American southwest. Today’s cool image on the right, cropped and reduced to post here, is a typical example. Photographed on September 7, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), it shows a dramatic cliff face that I estimate is about 3,000 feet high.
A closer look, however, almost always shows that this Martian terrain is not like the American southwest at all, but alien in its own way.
At the base of this abrupt cliff the terrain suddenly changes to a series of smooth downward fan-shaped flows. The cliff evokes rough boulders, avalanches, and chaotic erosion. The fans evoke a gentle and organized erosion of small particles like dust or sand. The two processes are completely different, and yet here the former is butted right up against the latter.
The fans also appear to flow out of hollows in the rough cliff, suggesting that somehow as the cliff erodes in chunks those chunks break into sand or dust, find the lowest points, and then flow downward like liquid.
How strange. How Martian. And how truly beautiful.
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
Many features on Mars immediately make one think of the Grand Canyon and the stark dramatic geology of the American southwest. Today’s cool image on the right, cropped and reduced to post here, is a typical example. Photographed on September 7, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), it shows a dramatic cliff face that I estimate is about 3,000 feet high.
A closer look, however, almost always shows that this Martian terrain is not like the American southwest at all, but alien in its own way.
At the base of this abrupt cliff the terrain suddenly changes to a series of smooth downward fan-shaped flows. The cliff evokes rough boulders, avalanches, and chaotic erosion. The fans evoke a gentle and organized erosion of small particles like dust or sand. The two processes are completely different, and yet here the former is butted right up against the latter.
The fans also appear to flow out of hollows in the rough cliff, suggesting that somehow as the cliff erodes in chunks those chunks break into sand or dust, find the lowest points, and then flow downward like liquid.
How strange. How Martian. And how truly beautiful.
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
What a great shot! Thanks Bob.
Alternatively, or additionally, could not material from the upper plateau spill down the crevices? Geology seems to happen slowly on Mars, due to temperature and gravity.
I’ve been looking at this incredibly alien landscape for a while. Things like this awe me. One of the reasons I come here is to get my fix of alien inspired awe.
And the tiny little mysteries that I will never understand, like that little bright “ball” on the “beach” in the lower left. All by itself. Looks like it rolled down a hill of low-g quicksand.
My, my……
I must say I really enjoy these cool and very compelling images. In spite of all
our earthly troubles, it is good to be reminded that there is an entire solar system
for us to explore, just waiting for us!
Let me throw in my 2 cents worth: if you look just below the top edge of the cliff
there appear to be darker bands of material running lengthwise. Is this some kind
of sedimentary rock? “Sandstone?” Even if the bedrock here is volcanic, consider that
on Earth, pumice is very light weight and crumbly.
My conjecture is that no matter how imposing this cliff may appear, the material
of which it is made is rather insubstantial and erosion causes it to crumble directly
into fine sand or dust.
And thank you, pawn, for pointing out that “beach ball.” Some Martian kids were
probably playing volleyball and lost it. Their parents will be upset that they lost an
expensive toy.
Perhaps the rough cliff is NOT eroding, and the fans are just sand/dust that was blown off the top & fell into place, rather than making a dune pile. This would explain the lack of large debris at the base of the fans.