The edge of a vast frozen lava sea on Mars
Click for original image.
Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on February 10, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists label boringly “Lava Interactions with Landscape.”
What is the lava, and what is the landscape? Here’s is my initial guess, based simply on looking at this image alone. The mound in the middle is the landscape, the rounded top of a very ancient mountain or hill. The flat plain that surrounds it is flood lava, that in the far past poured in and mostly buried the mountain.
Everything here signals a very old terrain. To get this mountain worn so smooth from the thin Martian atmosphere has to have taken more than a billion years. And that flood lava has to also be as old, because of the number of craters on its surface. I don’t know the impact rate, but I know it takes time to accumulate this number of impacts.
The sense of age is further underlined by the moat that surrounds the hill. When that lava poured in, it would have flooded right up to the mountain slope. Over time the weakest section of lava, most prone to erosion, would be that contact point. To wear it away as we now see it must have taken many eons.
All these speculations are a very unreliable guesses. To get a better understanding of this terrain it is essential we look at more than this picture alone.
The white dot on the overview map to the right marks the location. The inset shows the area in the white box in detail.
Very obviously, this location marks the outermost edge of the vast flood lava plain that surrounds Mars’ giant volcanoes, with Arsia Mons the nearest and also thought to be one of the youngest. Though researchers believe that the caldera at the summit was most active about 150 million years ago, the flood plain that surrounds all these giant volcanoes is estimated to have formed much earlier, from 3 to 3.7 billion years ago. It was then that this flood of lava poured out and covered everything right up to those mountains and craters only a few miles to the west.
The rounded hills in this picture have to be even older. We are therefore looking at some very primeval Martian terrain, far older than my initial estimate of a billion years. It marks a time almost four billion years ago when Mars was a planet of erupting volcanoes and seas of molton lava, now frozen.
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.
Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on February 10, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists label boringly “Lava Interactions with Landscape.”
What is the lava, and what is the landscape? Here’s is my initial guess, based simply on looking at this image alone. The mound in the middle is the landscape, the rounded top of a very ancient mountain or hill. The flat plain that surrounds it is flood lava, that in the far past poured in and mostly buried the mountain.
Everything here signals a very old terrain. To get this mountain worn so smooth from the thin Martian atmosphere has to have taken more than a billion years. And that flood lava has to also be as old, because of the number of craters on its surface. I don’t know the impact rate, but I know it takes time to accumulate this number of impacts.
The sense of age is further underlined by the moat that surrounds the hill. When that lava poured in, it would have flooded right up to the mountain slope. Over time the weakest section of lava, most prone to erosion, would be that contact point. To wear it away as we now see it must have taken many eons.
All these speculations are a very unreliable guesses. To get a better understanding of this terrain it is essential we look at more than this picture alone.
The white dot on the overview map to the right marks the location. The inset shows the area in the white box in detail.
Very obviously, this location marks the outermost edge of the vast flood lava plain that surrounds Mars’ giant volcanoes, with Arsia Mons the nearest and also thought to be one of the youngest. Though researchers believe that the caldera at the summit was most active about 150 million years ago, the flood plain that surrounds all these giant volcanoes is estimated to have formed much earlier, from 3 to 3.7 billion years ago. It was then that this flood of lava poured out and covered everything right up to those mountains and craters only a few miles to the west.
The rounded hills in this picture have to be even older. We are therefore looking at some very primeval Martian terrain, far older than my initial estimate of a billion years. It marks a time almost four billion years ago when Mars was a planet of erupting volcanoes and seas of molton lava, now frozen.
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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