Buried peaks in a sea of Martian sand
Click for original image.
Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on April 13, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the MRO science team labels as “streamlined features”, though that doesn’t seem to me to be the best description.
Granted, the prevailing winds, from the northeast to the southwest, appear to pushing the sand dune fields to the southwest. The dark line — created recently by a dust devil — indicates the wind direction. The mesas, from 100 to 200 feet high, do not however appear very streamlined. Instead, they simply look like they are poking up through this sea of sand and dunes, with the wind able over time to successfully push that sand uphill a hundred-plus feet into the saddle between the mesas.
The overview map below provides some context and possibly an explanation, though not a very conclusive one.
The rectangle in the inset marks the location of these mesas, in the northern interior of Argyre Basin. Though the latitude, 48 degrees south, suggests they should be near surface ice, the picture shows no sign of such. Instead, the inset shows that these mesas line up as a series of parallel north-south oriented ridges, placed down before the impact that created the unnamed 12-mile-wide eroded crater to the northeast.
Thus, the geology here implies the mesas are very ancient mountain peaks formed a very long time ago. Argyre Basin is thought to have been formed by a giant impact about four billion years ago, during what scientists label the Late Heavy Bombarment when the planets were coalescing. Later it is believed the basin was covered with a thick ice sheet and possibly even a lake. As that water sublimated away the parallel ridges could have been caused by glaciers flowing.
Or possibly these ridges are volcanic in nature, as suggested by the pit at the top of the bottommost mesa in the picture above. The ridges could have originally been cracks formed from the large impact to the north, radiating away to the south. Any lava that pushed up through those cracks could have been more resistent to erosion, so that over time the cracks became the parallel lines of peaks we see today.
This is all very speculative however. What appears evident however is that the peaks/mesas are the tops of very ancient mountains, buried beneath material that was placed there later.
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
Click for original image.
Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on April 13, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the MRO science team labels as “streamlined features”, though that doesn’t seem to me to be the best description.
Granted, the prevailing winds, from the northeast to the southwest, appear to pushing the sand dune fields to the southwest. The dark line — created recently by a dust devil — indicates the wind direction. The mesas, from 100 to 200 feet high, do not however appear very streamlined. Instead, they simply look like they are poking up through this sea of sand and dunes, with the wind able over time to successfully push that sand uphill a hundred-plus feet into the saddle between the mesas.
The overview map below provides some context and possibly an explanation, though not a very conclusive one.
The rectangle in the inset marks the location of these mesas, in the northern interior of Argyre Basin. Though the latitude, 48 degrees south, suggests they should be near surface ice, the picture shows no sign of such. Instead, the inset shows that these mesas line up as a series of parallel north-south oriented ridges, placed down before the impact that created the unnamed 12-mile-wide eroded crater to the northeast.
Thus, the geology here implies the mesas are very ancient mountain peaks formed a very long time ago. Argyre Basin is thought to have been formed by a giant impact about four billion years ago, during what scientists label the Late Heavy Bombarment when the planets were coalescing. Later it is believed the basin was covered with a thick ice sheet and possibly even a lake. As that water sublimated away the parallel ridges could have been caused by glaciers flowing.
Or possibly these ridges are volcanic in nature, as suggested by the pit at the top of the bottommost mesa in the picture above. The ridges could have originally been cracks formed from the large impact to the north, radiating away to the south. Any lava that pushed up through those cracks could have been more resistent to erosion, so that over time the cracks became the parallel lines of peaks we see today.
This is all very speculative however. What appears evident however is that the peaks/mesas are the tops of very ancient mountains, buried beneath material that was placed there later.
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
Readers: the rules for commenting!
No registration is required. I welcome all opinions, even those that strongly criticize my commentary.
However, name-calling and obscenities will not be tolerated. First time offenders who are new to the site will be warned. Second time offenders or first time offenders who have been here awhile will be suspended for a week. After that, I will ban you. Period.
Note also that first time commenters as well as any comment with more than one link will be placed in moderation for my approval. Be patient, I will get to it.