Spring etch-a-sketch near the Martian south pole
Click for original image.
Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on May 28, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled merely as a “terrain sample,” it was likely snapped not as part of any specific research project but to fill a gap in the camera’s schedule so as to maintain its proper temperature.
The camera team tries to find interesting geology when they do this, and are frequently successful. In this case the image shows some truly alien Martian terrain at 77 degrees south latitude, about 475 miles from the south pole.
What are we looking at? I promise you it isn’t the iron filings found inside an Etch-A-Sketch drawing toy. My guess is that the base layer is the light areas, a mixture of ice and debris impregnated with dust and eroded into the unique Martian geological feature dubbed brain terrain. As for the dark lines and splotches, their explanation might lie in the time of year, the spring.
The white dot near the top of the overview map to the right marks the location of this picture. During the winter months the carbon dioxide in the Martian atmosphere will fall as snow, covering the polar regions down to 60 degrees latitude with a thin mantle of transparent dry ice. When spring arrives the sunlight hits the base below this mantle, heats it, and causes that mantle to sublimate into gas, from the bottom up.
The gas however is trapped. In the southern hemisphere it will follow the same topography upward year after year until it finds a weak point in the mantle. There the mantle cracks, and the gas bursts out, spewing dark dust on top of the mantle. As it was spring when this photo was taken, the dark lines and splotches are where those cracks have appeared, releasing the dust onto the mantle.
The dark lines are thus outlining the topography of brain terrain at this location. They don’t explain the process that forms brain terrain (it remains unexplained) but they do delineate it for us.
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 May 28, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled merely as a “terrain sample,” it was likely snapped not as part of any specific research project but to fill a gap in the camera’s schedule so as to maintain its proper temperature.
The camera team tries to find interesting geology when they do this, and are frequently successful. In this case the image shows some truly alien Martian terrain at 77 degrees south latitude, about 475 miles from the south pole.
What are we looking at? I promise you it isn’t the iron filings found inside an Etch-A-Sketch drawing toy. My guess is that the base layer is the light areas, a mixture of ice and debris impregnated with dust and eroded into the unique Martian geological feature dubbed brain terrain. As for the dark lines and splotches, their explanation might lie in the time of year, the spring.
The white dot near the top of the overview map to the right marks the location of this picture. During the winter months the carbon dioxide in the Martian atmosphere will fall as snow, covering the polar regions down to 60 degrees latitude with a thin mantle of transparent dry ice. When spring arrives the sunlight hits the base below this mantle, heats it, and causes that mantle to sublimate into gas, from the bottom up.
The gas however is trapped. In the southern hemisphere it will follow the same topography upward year after year until it finds a weak point in the mantle. There the mantle cracks, and the gas bursts out, spewing dark dust on top of the mantle. As it was spring when this photo was taken, the dark lines and splotches are where those cracks have appeared, releasing the dust onto the mantle.
The dark lines are thus outlining the topography of brain terrain at this location. They don’t explain the process that forms brain terrain (it remains unexplained) but they do delineate it for us.
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
Those are clearly the monsters from ATTACK THE BLOCK circling the Kaaba