Endless ash fields on Mars
Click for original image.
Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on September 18, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).
It shows the very typical surface on a high plateau in Mars’ dry tropical regions. The dunes you see here, in this very small slice, cover a region about 80 miles square, with the prevailing winds appearing to consistently blow from the northeast to the southwest and forming these endless striations.
The dunes are made of volcanic ash, and the size of this particular ash field gives us a sense of the past volcanic activity that once dominated the red planet. Once, the atmosphere was filled with ash, which covered the ground across large regions. In the subsequent eons the thin Martian atmosphere has reshaped and piled that ash into giant mounds hundreds of miles across, with the surface striated as we see here.
The white dot on the overview map to the right marks the location, in a region dubbed Memnonia Sulcia, located at about 8 degrees south latitude in the region of Mars I label volcano country because its entire surface seems shaped by some kind of volcanic process, either lava flows or ash fields or volcanic cones or giant volcanoes.
In this case, the ash that covers Memnonia Sulci is all part of the biggest ash field on Mars, dubbed the Medusae Fossae Formation. Medusae in total covers an area equivalent to the subcontinent of India, and is believed to be the source of most of the red dust that gives the red planet its nickname.
No matter how advanced in technology and terra-forming the future colonists of Mars become, I don’t believe this will ever be a popular place to live. No water, no minerals, no worthwhile resources. Its only advantage is its location near the warmer equator, but there are many other places in the Martian tropics that will likely be far more hospitable.
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 or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. 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 image.
Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on September 18, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).
It shows the very typical surface on a high plateau in Mars’ dry tropical regions. The dunes you see here, in this very small slice, cover a region about 80 miles square, with the prevailing winds appearing to consistently blow from the northeast to the southwest and forming these endless striations.
The dunes are made of volcanic ash, and the size of this particular ash field gives us a sense of the past volcanic activity that once dominated the red planet. Once, the atmosphere was filled with ash, which covered the ground across large regions. In the subsequent eons the thin Martian atmosphere has reshaped and piled that ash into giant mounds hundreds of miles across, with the surface striated as we see here.
The white dot on the overview map to the right marks the location, in a region dubbed Memnonia Sulcia, located at about 8 degrees south latitude in the region of Mars I label volcano country because its entire surface seems shaped by some kind of volcanic process, either lava flows or ash fields or volcanic cones or giant volcanoes.
In this case, the ash that covers Memnonia Sulci is all part of the biggest ash field on Mars, dubbed the Medusae Fossae Formation. Medusae in total covers an area equivalent to the subcontinent of India, and is believed to be the source of most of the red dust that gives the red planet its nickname.
No matter how advanced in technology and terra-forming the future colonists of Mars become, I don’t believe this will ever be a popular place to live. No water, no minerals, no worthwhile resources. Its only advantage is its location near the warmer equator, but there are many other places in the Martian tropics that will likely be far more hospitable.
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 or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. 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
Bob,
Something is off here. You went west one too many times.
” with the prevailing winds appearing to consistently blow from the northwest to the southwest”
Regardless, it’s a fascinating landscape.
Tom, good catch! When I read it my mind saw “southeast”! My question is how tall are these dunes? How do they compare to the dunes of the Sahara, for example?
Tom: It should have been “northeast”. I have fixed it. Thank you.
I am aware that there are types of dunes that form with their long-axis parallel to the prevailing winds (“seif”), and perpendicular to it (“transverse”). According to your description, these would be seif. Not sure what causes one versus the other on Mars, or if there are multiple types on Mars?