Unknown Mars
Click for interactive global mosaic.
Cool image time! The picture to the right was created from a global mosaic of all the context camera images taken by Mars Reconnaissance Orbiter (MRO) since it entered Mars orbit in 2006. It shows an unnamed 17-mile-wide-depression located only about seven miles south of the southern rim of Valles Marineris.
I highlight this particular depression because, despite seventeen years in orbit, MRO’s high resolution camera has at this time still not taken any pictures inside or around it. This is a place on Mars that remains unstudied in detail, in any way, even though its depth is comparable to the Grand Canyon and its features strongly suggest its is a collapse feature, created when the roof over an underground void gave way. If so, it suggests an origin for Valles Marineris that conflicts with present theories.
The depression in the middle of the inset on the overview map to the right is this unnamed depression. Some numbers: The drop from rim to floor ranges from 4,000 to 6,000 feet. The small hills inside the depression range in height from only about 30 feet to as much as 3,700 feet. All remind me of cave breakdown piles that have become partly buried by debris as well as eroded over time from wind.
Breakdown piles in caves come from ceiling collapses. If this is a collapse feature it suggests that much of Valles Marineris was formed in a similar way. The present most accepted theory — not confirmed — is that catastrophic floods of water carved the giant canyon. If formed underground, however, that suggests that the process was likely not catastrophic. Instead, the material was slowly washed out until the roof fell in, leaving behind that gigantic canyon.
All of this speculation is the equivalent of blindly throwing darts at a wall, and hoping something hits bullseye. For example, was glacial activity involved? What was this region like on Mars in the far past, when it is thought there was more water on the planet? How does the wide swings in the planet’s rotational tilt and the accompanying climate cycles factor in? How did the many volcanic eruptions that laid down numerous layers in Valles Marineris impact this formation process?
The bottom line remains: No detailed study of this unnamed depression has yet occurred, because Mars is a planet with as much surface area as all the continents on Earth. There is a lot to study here, and we have only been doing it for less than a half century, and almost all only from orbit.
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 interactive global mosaic.
Cool image time! The picture to the right was created from a global mosaic of all the context camera images taken by Mars Reconnaissance Orbiter (MRO) since it entered Mars orbit in 2006. It shows an unnamed 17-mile-wide-depression located only about seven miles south of the southern rim of Valles Marineris.
I highlight this particular depression because, despite seventeen years in orbit, MRO’s high resolution camera has at this time still not taken any pictures inside or around it. This is a place on Mars that remains unstudied in detail, in any way, even though its depth is comparable to the Grand Canyon and its features strongly suggest its is a collapse feature, created when the roof over an underground void gave way. If so, it suggests an origin for Valles Marineris that conflicts with present theories.
The depression in the middle of the inset on the overview map to the right is this unnamed depression. Some numbers: The drop from rim to floor ranges from 4,000 to 6,000 feet. The small hills inside the depression range in height from only about 30 feet to as much as 3,700 feet. All remind me of cave breakdown piles that have become partly buried by debris as well as eroded over time from wind.
Breakdown piles in caves come from ceiling collapses. If this is a collapse feature it suggests that much of Valles Marineris was formed in a similar way. The present most accepted theory — not confirmed — is that catastrophic floods of water carved the giant canyon. If formed underground, however, that suggests that the process was likely not catastrophic. Instead, the material was slowly washed out until the roof fell in, leaving behind that gigantic canyon.
All of this speculation is the equivalent of blindly throwing darts at a wall, and hoping something hits bullseye. For example, was glacial activity involved? What was this region like on Mars in the far past, when it is thought there was more water on the planet? How does the wide swings in the planet’s rotational tilt and the accompanying climate cycles factor in? How did the many volcanic eruptions that laid down numerous layers in Valles Marineris impact this formation process?
The bottom line remains: No detailed study of this unnamed depression has yet occurred, because Mars is a planet with as much surface area as all the continents on Earth. There is a lot to study here, and we have only been doing it for less than a half century, and almost all only from orbit.
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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