A journey into Martian chaos
With today’s cool image, we shall begin with the overview map, and drill our way down until we get a close look at another example of truly alien Martian terrain, with only a hint of similarity to comparable geology on Earth.
The overview map to the right shows us Aram Chaos, an ancient 170-mile-wide impact crater that has gone through such complex geology that it is difficult, maybe impossible, to unravel it based on data obtained from orbit. As I wrote in a detailed December 2020 post describing the confusing geology of this crater,
The floor of Aram Chaos is a place of great puzzlement to planetary geologists. The geology there is incredibly complex, and includes chaos terrain overlain by several sedimentary layers of sulfate minerals. The chaos terrain is most obvious in the southern part of the crater’s floor. The flat areas near the eastern center are those overlaying sedimentary layers.
When we zoom into the white box we can see a good example of this complexity.
Click for full image.
The picture to the right, rotated, cropped, and reduced to post here, was taken by the context camera on Mars Reconnaissance Orbiter (MRO) on December 12, 2013. It provides us a wide view of the flat regions in the middle of Aram Chaos, with several chaotic blocks of bedrock sticking up like fractured islands.
The second picture to the right, rotated and cropped to post here, was taken on January 29, 2023 by MRO’s high resolution camera. The white box in the context camera picture above indicates the area covered.
The rough white surface material is neither ice, lava, nor frost. As Chris Okubo of the U.S. Geological Survey explained to me in 2020, “These are sedimentary rocks comprised primarily of sulfates. The texture to me suggests these are lithified dunes.”
Lithified merely means that the dunes have hardened into rock. Sulfates are a salt formed from sulfuric acid, and are on Mars often linked to some complex mineralogy. If you stood there the colors would be white and red, quite beautiful. As Okubo further explained, “The sulfates are white to tan in color, but there would also be a lot of red/brown Mars dust on top of it. It would be similar to walking around some of the playas in the desert southwest.”
This white sulfate material, now similar to gypsum and safe to touch, immediately reminds me of the sponge terrain I highlighted in a cool image just last week. That terrain however was dark, while this is light.
Are they related? Darned if I know. In the case of Aram Chaos, the data suggests these dunes might have once covered the entire floor of the crater. First they were sand blown into dunes by the wind. Then they hardened into rock, and the wind, other chemical processes, and above all time has been slowly eroding them down to expose the bedrock of chaos terrain below.
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
With today’s cool image, we shall begin with the overview map, and drill our way down until we get a close look at another example of truly alien Martian terrain, with only a hint of similarity to comparable geology on Earth.
The overview map to the right shows us Aram Chaos, an ancient 170-mile-wide impact crater that has gone through such complex geology that it is difficult, maybe impossible, to unravel it based on data obtained from orbit. As I wrote in a detailed December 2020 post describing the confusing geology of this crater,
The floor of Aram Chaos is a place of great puzzlement to planetary geologists. The geology there is incredibly complex, and includes chaos terrain overlain by several sedimentary layers of sulfate minerals. The chaos terrain is most obvious in the southern part of the crater’s floor. The flat areas near the eastern center are those overlaying sedimentary layers.
When we zoom into the white box we can see a good example of this complexity.
Click for full image.
The picture to the right, rotated, cropped, and reduced to post here, was taken by the context camera on Mars Reconnaissance Orbiter (MRO) on December 12, 2013. It provides us a wide view of the flat regions in the middle of Aram Chaos, with several chaotic blocks of bedrock sticking up like fractured islands.
The second picture to the right, rotated and cropped to post here, was taken on January 29, 2023 by MRO’s high resolution camera. The white box in the context camera picture above indicates the area covered.
The rough white surface material is neither ice, lava, nor frost. As Chris Okubo of the U.S. Geological Survey explained to me in 2020, “These are sedimentary rocks comprised primarily of sulfates. The texture to me suggests these are lithified dunes.”
Lithified merely means that the dunes have hardened into rock. Sulfates are a salt formed from sulfuric acid, and are on Mars often linked to some complex mineralogy. If you stood there the colors would be white and red, quite beautiful. As Okubo further explained, “The sulfates are white to tan in color, but there would also be a lot of red/brown Mars dust on top of it. It would be similar to walking around some of the playas in the desert southwest.”
This white sulfate material, now similar to gypsum and safe to touch, immediately reminds me of the sponge terrain I highlighted in a cool image just last week. That terrain however was dark, while this is light.
Are they related? Darned if I know. In the case of Aram Chaos, the data suggests these dunes might have once covered the entire floor of the crater. First they were sand blown into dunes by the wind. Then they hardened into rock, and the wind, other chemical processes, and above all time has been slowly eroding them down to expose the bedrock of chaos terrain below.
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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