Alien Mars
Click for original image.
Today’s cool image illustrates again the alien geology of Mars, often disguised as geological features that at first glance seem familiar. The picture to the right, cropped and reduced to post here, was taken on April 9, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Its most distinct feature, the mile-wide double crater in the center bottom, at first appears typical of such craters found on the Moon and elsewhere, suggesting that the bolide that caused it broke in two as it cut through the Martian atmosphere.
This double crater however is not like lunar double craters, in that the shape of both craters is deformed, and the deformation is not quite the same in each. Moreover, the crater does not appear to have an upraised rim or to have thrown out any obvious ejecta. Instead, the two objects hit what looks like soft ground, such as when you drop a pebble into snow.
There’s more.
The white dot east of Alba Mons on the overview map to the right marks this location, in the region to the northeast of Mars’ great volcanoes that is filled with parallel fissures, all oriented from the northeast to the southwest and aligned with the 3,500-mile-long fault line that appears linked to the formation of those giant volcanoes.
The ground here is likely hardened lava, but the surface appears soft like ice. The canyon running from the northeast to the southwest just north of this double crater is probably a graben, a fissure created when two large sections of ground separate or slip sideways in opposite directions. This hypothesis is strengthened in that the north wall is about 500 feet high while the south wall is only 400 feet high. The two halves shifted, but a different amount. The canyon looks soft too, with its floor having both dunes and glacial features. Similarly, the other small craters south of the canyon also look soft, and all appear to have glacial material and dunes in their interiors.
Finally there is the dark streak flowing down from the canyon’s south wall. This is a slope streak, a feature unique to Mars whose formation is not yet understood. There are theories, from a dust avalanche to seepage, but none seems to fit the facts entirely.
As I have said before, Mars is strange and wonderful, but mostly alien. We really won’t understand it fully until we recognize this, and stop applying our Earth-based assumptions upon it.
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 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 illustrates again the alien geology of Mars, often disguised as geological features that at first glance seem familiar. The picture to the right, cropped and reduced to post here, was taken on April 9, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Its most distinct feature, the mile-wide double crater in the center bottom, at first appears typical of such craters found on the Moon and elsewhere, suggesting that the bolide that caused it broke in two as it cut through the Martian atmosphere.
This double crater however is not like lunar double craters, in that the shape of both craters is deformed, and the deformation is not quite the same in each. Moreover, the crater does not appear to have an upraised rim or to have thrown out any obvious ejecta. Instead, the two objects hit what looks like soft ground, such as when you drop a pebble into snow.
There’s more.
The white dot east of Alba Mons on the overview map to the right marks this location, in the region to the northeast of Mars’ great volcanoes that is filled with parallel fissures, all oriented from the northeast to the southwest and aligned with the 3,500-mile-long fault line that appears linked to the formation of those giant volcanoes.
The ground here is likely hardened lava, but the surface appears soft like ice. The canyon running from the northeast to the southwest just north of this double crater is probably a graben, a fissure created when two large sections of ground separate or slip sideways in opposite directions. This hypothesis is strengthened in that the north wall is about 500 feet high while the south wall is only 400 feet high. The two halves shifted, but a different amount. The canyon looks soft too, with its floor having both dunes and glacial features. Similarly, the other small craters south of the canyon also look soft, and all appear to have glacial material and dunes in their interiors.
Finally there is the dark streak flowing down from the canyon’s south wall. This is a slope streak, a feature unique to Mars whose formation is not yet understood. There are theories, from a dust avalanche to seepage, but none seems to fit the facts entirely.
As I have said before, Mars is strange and wonderful, but mostly alien. We really won’t understand it fully until we recognize this, and stop applying our Earth-based assumptions upon it.
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 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
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