“Round Deposits” in Martian crater
Click for original image.
Today’s cool image could also be entered into my “What the heck?!” category of strange Martian geology. The picture to the right, cropped, reduced, and sharpened to post here, was taken on October 19, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).
The science team labels this as “Round Deposits in Crater.” And yup, that’s what we have, round and flat small mesas inside an unnamed 3,500-foot-wide very shallow crater (no more than 10-20 feet deep) that also appears to be sitting higher than the surrounding landscape. Furthermore, several nearby craters are also raised, with one having its own oblong flat interior mesa. Moreover, the terrain around the crater appears stippled, as if it has been eroding or sublimating away.
The latitude, 37 degrees north, provides the first clue for explaining this weird landscape.
The white dot on the overview map to the right marks the location, on the northern edge of Arabia Terra, the largest transition zone on Mars between its southern cratered highlands and its northern lowland plains. This location is also in the mid-latitudes, where lots of glacial features are routinely found. It is also near the region dubbed Cydonia, where the mesa I call “the non-face on Mars” is located and is a region with lots of weird mesas.
The raised craters at this location appear to be examples what scientists dub “expanded craters,” impacts that occurred in near surface ice and have been reshaped by the ice’s melting and sublimation, both at impact and then later. Why this crater should have these round flat mesas on its floor however is not clear.
The inset shows that the weird geology is not limited to round deposits, expanded craters, and weird mesas. To the north about forty miles away is a very strange mottled distorted depression dubbed Ismenia Patera, a feature whose origin remains unknown. It could be an impact crater that has become distorted over time due to the sublimation of the ample near-surface ice and glaciers in these latitudes. Or it could be the caldera of an ancient volcano that has also become distorted for the same reasons.
It is also likely that impacts and volcanic activity both played a part in shaping this landscape, combined with the presence of a lot of near surface ice, impregnated within the topsoil.
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.
Today’s cool image could also be entered into my “What the heck?!” category of strange Martian geology. The picture to the right, cropped, reduced, and sharpened to post here, was taken on October 19, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).
The science team labels this as “Round Deposits in Crater.” And yup, that’s what we have, round and flat small mesas inside an unnamed 3,500-foot-wide very shallow crater (no more than 10-20 feet deep) that also appears to be sitting higher than the surrounding landscape. Furthermore, several nearby craters are also raised, with one having its own oblong flat interior mesa. Moreover, the terrain around the crater appears stippled, as if it has been eroding or sublimating away.
The latitude, 37 degrees north, provides the first clue for explaining this weird landscape.
The white dot on the overview map to the right marks the location, on the northern edge of Arabia Terra, the largest transition zone on Mars between its southern cratered highlands and its northern lowland plains. This location is also in the mid-latitudes, where lots of glacial features are routinely found. It is also near the region dubbed Cydonia, where the mesa I call “the non-face on Mars” is located and is a region with lots of weird mesas.
The raised craters at this location appear to be examples what scientists dub “expanded craters,” impacts that occurred in near surface ice and have been reshaped by the ice’s melting and sublimation, both at impact and then later. Why this crater should have these round flat mesas on its floor however is not clear.
The inset shows that the weird geology is not limited to round deposits, expanded craters, and weird mesas. To the north about forty miles away is a very strange mottled distorted depression dubbed Ismenia Patera, a feature whose origin remains unknown. It could be an impact crater that has become distorted over time due to the sublimation of the ample near-surface ice and glaciers in these latitudes. Or it could be the caldera of an ancient volcano that has also become distorted for the same reasons.
It is also likely that impacts and volcanic activity both played a part in shaping this landscape, combined with the presence of a lot of near surface ice, impregnated within the topsoil.
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