A pimple on Mars
Click for original image.
Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on November 1, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled simply as a “terrain sample,” it was likely not taken as part of any specific research project, but to fill a gap in the camera’s schedule in order to maintain its proper temperature. When the camera team does this they try to pick something interesting, and sometimes succeed.
I think they succeeded in this case. At first glance this appears to be a crater, but on closer inspection it is instead a small mound. The picture was taken in the winter, at the high latitude of 55 degrees north. The featureless white surface surrounding this dark mound is almost certainly the mantle of dry ice that falls as snow and covers the poles during the winter. If not that, it is then likely to be a water ice sheet that orbital data suggests covers much of Mars’ high latitudes.
The white dot on the overview map to the right marks the location, deep within the northern lowland plains.
The white streaks that resemble cracks on the surface of the mound very likely are tracks created by that mantle of dry ice as it sublimates each spring back into gas. The sun shines through the clear dry ice, heats it at its base. The trapped gas flows along pathways (the white streaks) to find the weak point in the mantle, where the pressures causes it to break, allowing the gas to escape. In the southern hemisphere the ground is stable enough that these flow routes repeat from year to year and become very distinct. In the northern hemisphere the ground is usually not that stable, and thus the flow usually finds different routes from year to year.
This mound however appears more stable, and so the gas flows each year have deepened the cracks and made them stand out.
That is my theory based on what little I know of Martian geology. It is possible that I am completely wrong, and this mound and the white streaks are caused from an entirely different process.
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, cropped, reduced, and sharpened to post here, was taken on November 1, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled simply as a “terrain sample,” it was likely not taken as part of any specific research project, but to fill a gap in the camera’s schedule in order to maintain its proper temperature. When the camera team does this they try to pick something interesting, and sometimes succeed.
I think they succeeded in this case. At first glance this appears to be a crater, but on closer inspection it is instead a small mound. The picture was taken in the winter, at the high latitude of 55 degrees north. The featureless white surface surrounding this dark mound is almost certainly the mantle of dry ice that falls as snow and covers the poles during the winter. If not that, it is then likely to be a water ice sheet that orbital data suggests covers much of Mars’ high latitudes.
The white dot on the overview map to the right marks the location, deep within the northern lowland plains.
The white streaks that resemble cracks on the surface of the mound very likely are tracks created by that mantle of dry ice as it sublimates each spring back into gas. The sun shines through the clear dry ice, heats it at its base. The trapped gas flows along pathways (the white streaks) to find the weak point in the mantle, where the pressures causes it to break, allowing the gas to escape. In the southern hemisphere the ground is stable enough that these flow routes repeat from year to year and become very distinct. In the northern hemisphere the ground is usually not that stable, and thus the flow usually finds different routes from year to year.
This mound however appears more stable, and so the gas flows each year have deepened the cracks and made them stand out.
That is my theory based on what little I know of Martian geology. It is possible that I am completely wrong, and this mound and the white streaks are caused from an entirely different process.
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
Robert,
I suspect that if we look at it from far enough away, we would call it a beauty mark on Mars.