Martian crater and mesa sculpted by ancient flow
Click for full image.
Cool image time! The picture to the right, rotated, cropped, and reduced to post here, was taken on June 15, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a crater whose ejecta has been sculpted to the east into a teardrop-shaped mesa by some ancient flow, coming from the west.
The crater itself is located in one of several outflow canyons draining out from the volcanic Tharsis Bulge into the northern lowland plain of Chryse Planitia, the biggest of which is Valles Marineris. This particular canyon is one of the smaller and is dubbed Ravi Vallis.
The overview map below illustrates why many scientists think the flow that shaped this mesa came from a catastrophic flood of liquid water, billions of years ago.
The black dot on the equator about 1,300 miles to the west of Opportunity’s landing site marks the location of this mesa.
Note the theorized inland sea. In analyzing data from orbiters as well as from Mars Pathfinder, a team of scientists in 2019 had proposed the past existence of these relative shallow bodies of water, produced by the floods that had poured out from Tharsis 3.4 billion years ago.
Those floods could easily have carved this mesa. However, since no model has yet made it possible convincingly for liquid water to have existed on the surface of Mars, due to its cold climate and thin atmosphere, those floods remain nothing more than conjecture. One can’t help wondering if glaciers might have been a factor, considering the amount of glaciers found farther from the equator and which have heavily shaped the surface of Mars. Going back 3.4 billion years ago, Mars had lots more water, with most of it probably existing as ice. The accumulating research is beginning to suggest the possibility that the geological features we see that we assume were formed by liquid water might have instead been formed more slowly by flowing glaciers.
All guesswork, but good science requires that no hypothesis be accepted or dismissed out of hand. All must be considered.
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.
Cool image time! The picture to the right, rotated, cropped, and reduced to post here, was taken on June 15, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a crater whose ejecta has been sculpted to the east into a teardrop-shaped mesa by some ancient flow, coming from the west.
The crater itself is located in one of several outflow canyons draining out from the volcanic Tharsis Bulge into the northern lowland plain of Chryse Planitia, the biggest of which is Valles Marineris. This particular canyon is one of the smaller and is dubbed Ravi Vallis.
The overview map below illustrates why many scientists think the flow that shaped this mesa came from a catastrophic flood of liquid water, billions of years ago.
The black dot on the equator about 1,300 miles to the west of Opportunity’s landing site marks the location of this mesa.
Note the theorized inland sea. In analyzing data from orbiters as well as from Mars Pathfinder, a team of scientists in 2019 had proposed the past existence of these relative shallow bodies of water, produced by the floods that had poured out from Tharsis 3.4 billion years ago.
Those floods could easily have carved this mesa. However, since no model has yet made it possible convincingly for liquid water to have existed on the surface of Mars, due to its cold climate and thin atmosphere, those floods remain nothing more than conjecture. One can’t help wondering if glaciers might have been a factor, considering the amount of glaciers found farther from the equator and which have heavily shaped the surface of Mars. Going back 3.4 billion years ago, Mars had lots more water, with most of it probably existing as ice. The accumulating research is beginning to suggest the possibility that the geological features we see that we assume were formed by liquid water might have instead been formed more slowly by flowing glaciers.
All guesswork, but good science requires that no hypothesis be accepted or dismissed out of hand. All must be considered.
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
Thanks Bob. These are great. Please keep them coming.
I know this may sound silly and uninformed but why don’t they start a model with Mars having liquid water. It seems pretty obvious that models that can’t account for liquid water are wrong.
pawn asked: “I know this may sound silly and uninformed but why don’t they start a model with Mars having liquid water.”
Because the model would have to explain how Mars became the planet that it is today. One problem is figuring out a starting point that allows Mars to become so cold and airless that it can no longer hold liquid water. Finding that start point is difficult, especially with what we know right now.
Another problem is that, should we find a working model, there could be more than one starting point that could end with the current Mars, and if that is the case, then which starting point is correct? We also have to assure that the model itself is skilled at modeling reality, not at modeling wishful thinking.
We cannot simplify things and make any model that we want that gives the desired explanation or outcome. This is what they did with Earth’s climate change (AKA global warming, AKA the coming ice age). In the first decade of this century, the current models failed to predict the reality, so the climatologists chose to change the historic data in order to fit their models, and they failed to announce this change or to explain the changes — the users of the data figured it out on their own when they noticed that the post-modified data did not match the pre-modified data. As was taught in our early science classes, this is called fudging the data. The infamous email that recommended to “hide the decline” was a similar attempt to fudge the results of a model that used tree-ring data as a proxy for temperature — the decline was proof that the proxy was inappropriate for the task, and that it was incorrect to use the model.
Models only say what we tell them to say, so if we tell them to say what we want and not what is real then the conclusions do not match reality; they match only our fantasy. Modeling must be done carefully, otherwise they are not useful.