Martian channels formed by water? by ice? by lava?
Click for full image.
Many of the pictures from Mars show meandering channels, all of which suggest an erosion process related to some form of flow. For most of the last half century, since the first images of these channels were beamed back by Mariner 9 in 1972, scientists had believed that liquid water must have caused them. The accumulating recent photos from Mars now tentatively suggest that these channels might have instead been caused by glacial processes, creeping frozen water instead of liquid.
The image to the right, rotated, cropped, and reduced to post here, was taken on July 17, 2020 by the high resolution camera on Mars Reconnaissance Orbiter. The channels suggest some form of flow going downhill to the northwest, but was it caused by water or ice? There is no obvious visual evidence of glaciers in this image, nor is there any such evidence that I can spot in any of the nearby high resolution images of this same region, despite the fact that at 35 degrees north latitude it is in the mid-latitude band where scientists have identified many glacial features.
The region itself is called Mareotis Fossae, an area of southwest-to-northeast trending parallel fissures and ridges, as shown in the two overview maps below.
The white box in the top map indicates the area covered by the zoomed in bottom map. The cross in both maps indicates the location of today’s image.
Located about 800-1,000 miles east of the giant shield volcano Alba Mons and about 1,200 miles northeast of the Tharsis Bulge that contains Mars four largest volcanoes, there is ample evidence [pdf] that some sort of volcanic geologic process formed this terrain.
Yet the meandering channels in today’s image, coming down off of the north slope of one of this region’s many parallel ridges, do not appear volcanic in nature.
Water? Ice? Lava? Your guess is as good as mine.
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 full image.
Many of the pictures from Mars show meandering channels, all of which suggest an erosion process related to some form of flow. For most of the last half century, since the first images of these channels were beamed back by Mariner 9 in 1972, scientists had believed that liquid water must have caused them. The accumulating recent photos from Mars now tentatively suggest that these channels might have instead been caused by glacial processes, creeping frozen water instead of liquid.
The image to the right, rotated, cropped, and reduced to post here, was taken on July 17, 2020 by the high resolution camera on Mars Reconnaissance Orbiter. The channels suggest some form of flow going downhill to the northwest, but was it caused by water or ice? There is no obvious visual evidence of glaciers in this image, nor is there any such evidence that I can spot in any of the nearby high resolution images of this same region, despite the fact that at 35 degrees north latitude it is in the mid-latitude band where scientists have identified many glacial features.
The region itself is called Mareotis Fossae, an area of southwest-to-northeast trending parallel fissures and ridges, as shown in the two overview maps below.
The white box in the top map indicates the area covered by the zoomed in bottom map. The cross in both maps indicates the location of today’s image.
Located about 800-1,000 miles east of the giant shield volcano Alba Mons and about 1,200 miles northeast of the Tharsis Bulge that contains Mars four largest volcanoes, there is ample evidence [pdf] that some sort of volcanic geologic process formed this terrain.
Yet the meandering channels in today’s image, coming down off of the north slope of one of this region’s many parallel ridges, do not appear volcanic in nature.
Water? Ice? Lava? Your guess is as good as mine.
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
Perhaps less evidence of flowing water near these volcanoes, where lava probably dug out the features, as a contrast to regions without evidence of volcanoes where there are also river-like features, would indicate flowing water at the latter? Heck, there must be ways to, even from orbit, differ between lava channels and water channels!?
Fossie means “ditch”. And the name of the road where I live is Fossie. So that doesn’t sound so nice today: “ditch road”. But the main road that the Romans built in England was called the Fossie road. They built roads wherever they were, but in England they had to also dig ditches beside them. Because of the constant rain. So it was an especially big investment for them. Thus it has been an honorable name of roads everywhere since. (They did it for the gin!)
Talking about Mars, this income tax thing with Mr. Trump that obviously is planted as an issue for Tuesday’s debate:
– How much corporate tax has Trump paid?
– How much income has Trump gotten from the governments?
– And versus Joe Biden for both above!
Bringing up taxes, among the mess of everything else, seems like a big win for the Republicans. Debate watchers should think about where the taxes come from and where they go. I wonder whether the teleprompter AI figures out any winning lines at all for Yoyo Biden. I’m not a racist, but I don’t think that the Chinese are that smart yet.