Thick windblown ash in Mars’ largest mountain region
Click for original picture.
The cool image to the right, rotated, cropped, reduced, and sharpened to post here, was taken on September 1, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and shows what the scientists label as “Erosional Features on Olympus Mons.”
What is eroding? Based on the picture itself the first guess is volcanic ash, as these features strongly resemble the many features seen in the Medusae Fossae Formation, the largest volcanic ash field on Mars — about the size of the subcontinent of India.
Medusae however is many thousand miles away, and is not apparently related to any specific volcano. These features are instead directly linked to Olympus Mons, the largest known volcano in the solar system. However, much of the terrain for many hundreds of miles around Olympus is covered with flood lava, which was deposited and hardened quickly to form smooth featureless plains that have resisted much erosion over the eons. Here the terrain is clearly eroded, which suggests that if the material here is volcanic, it was laid down not by flood lava but by falling ash that got compressed but was easily friable and could be blown away by the winds of Mars’ thin atmosphere.
The red dot on the overview map to the right marks the location of this picture, in the center of the mountain region known as Lycus Sulci, the most extensive range of mountains on the Red Planet, about 1,400 mile wide and 1,800 miles long.
At present scientists are unsure of the geology that formed Lycus Sulci, and how it is linked with Olympus Mons. This picture however appears to be an attempt to solve that question. Its features also resemble a region south of Olympus Mons, and suggest that both are the ash remains of one or many of the volcano’s major eruptions. If so, the ash from those eruptions forms the many layers at this site, but its age has caused the top layers to be eroded significantly by the prevailing winds.
This picture, the picture of similar features south of Olympus, and the large size of Lycus Sulci all suggest that some of the eruptions of Olympus were inconceivably powerful explosive events, spreading gigantic amounts of ash across many thousands of miles of Mars. This possibility makes the past history of Mars even more alien. As alien from Earth as it is now, it was even stranger in the far past, a billion-plus years ago.
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 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
Click for original picture.
The cool image to the right, rotated, cropped, reduced, and sharpened to post here, was taken on September 1, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and shows what the scientists label as “Erosional Features on Olympus Mons.”
What is eroding? Based on the picture itself the first guess is volcanic ash, as these features strongly resemble the many features seen in the Medusae Fossae Formation, the largest volcanic ash field on Mars — about the size of the subcontinent of India.
Medusae however is many thousand miles away, and is not apparently related to any specific volcano. These features are instead directly linked to Olympus Mons, the largest known volcano in the solar system. However, much of the terrain for many hundreds of miles around Olympus is covered with flood lava, which was deposited and hardened quickly to form smooth featureless plains that have resisted much erosion over the eons. Here the terrain is clearly eroded, which suggests that if the material here is volcanic, it was laid down not by flood lava but by falling ash that got compressed but was easily friable and could be blown away by the winds of Mars’ thin atmosphere.
The red dot on the overview map to the right marks the location of this picture, in the center of the mountain region known as Lycus Sulci, the most extensive range of mountains on the Red Planet, about 1,400 mile wide and 1,800 miles long.
At present scientists are unsure of the geology that formed Lycus Sulci, and how it is linked with Olympus Mons. This picture however appears to be an attempt to solve that question. Its features also resemble a region south of Olympus Mons, and suggest that both are the ash remains of one or many of the volcano’s major eruptions. If so, the ash from those eruptions forms the many layers at this site, but its age has caused the top layers to be eroded significantly by the prevailing winds.
This picture, the picture of similar features south of Olympus, and the large size of Lycus Sulci all suggest that some of the eruptions of Olympus were inconceivably powerful explosive events, spreading gigantic amounts of ash across many thousands of miles of Mars. This possibility makes the past history of Mars even more alien. As alien from Earth as it is now, it was even stranger in the far past, a billion-plus years ago.
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 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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