Infeeder to a Martian paleolake
Click for original image.
Cool image time! The picture to the right, rotated, cropped, and reduced to post here, was taken on December 21, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists label as an “inlet to a paleolake.” I have used this context camera lower resolution image taken January 14, 2023 to fill in the blank central strip caused by a failed filter on the high resolution camera.
The elevation difference between the plateau on the lower left and the lake bottom on the upper right is about 700 feet. The inlet channel floor is about 200 feet below the plateau. We know it is ancient because of the number of small craters within it as well as on the lakebed below. It has been a very long time since any water or ice flowed down this channel to drain into the lake to the north.
While a lot of analysis of orbital data has found numerous examples of paleolakes in the dry equatoral regions of Mars (see here, here, here, here, and here , this particular example is so obvious not much analysis is needed, as shown in the overview map below.
The rectangle at the outlet of Shalbatana Vallis on the overview map to the right marks the location of the inset, with the tiny rectangle in the inset marking the area covered by the photo above. If you look close at the inset, you can see the outline of the paleolake, sitting about a mile above the lowland plains of Chryse Planitia. The topography suggests that the lake existed before either Shalbatana or Chryse existed, and became drained when the catastrophic floods poured out of Valles Marineris to carve out Shalbatana and Chryse.
Why those floods carved canyons on either side of the plateau that held this lake, rather than flowing down the 35-mile-long channel to the lake, is the fundamental geological mystery of this place. For some reason the flood or glacier that pushed down Shalbatana preferred going around. Fortunately, that fact allowed the lake to survive so that geologists now can see it. Had the flow gone through it it would have been washed away, leaving little obvious evidence it had ever existed.
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, rotated, cropped, and reduced to post here, was taken on December 21, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists label as an “inlet to a paleolake.” I have used this context camera lower resolution image taken January 14, 2023 to fill in the blank central strip caused by a failed filter on the high resolution camera.
The elevation difference between the plateau on the lower left and the lake bottom on the upper right is about 700 feet. The inlet channel floor is about 200 feet below the plateau. We know it is ancient because of the number of small craters within it as well as on the lakebed below. It has been a very long time since any water or ice flowed down this channel to drain into the lake to the north.
While a lot of analysis of orbital data has found numerous examples of paleolakes in the dry equatoral regions of Mars (see here, here, here, here, and here , this particular example is so obvious not much analysis is needed, as shown in the overview map below.
The rectangle at the outlet of Shalbatana Vallis on the overview map to the right marks the location of the inset, with the tiny rectangle in the inset marking the area covered by the photo above. If you look close at the inset, you can see the outline of the paleolake, sitting about a mile above the lowland plains of Chryse Planitia. The topography suggests that the lake existed before either Shalbatana or Chryse existed, and became drained when the catastrophic floods poured out of Valles Marineris to carve out Shalbatana and Chryse.
Why those floods carved canyons on either side of the plateau that held this lake, rather than flowing down the 35-mile-long channel to the lake, is the fundamental geological mystery of this place. For some reason the flood or glacier that pushed down Shalbatana preferred going around. Fortunately, that fact allowed the lake to survive so that geologists now can see it. Had the flow gone through it it would have been washed away, leaving little obvious evidence it had ever existed.
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
Is it just me or does that photo look like a massive (though 4-toed footprint? Cheers –