Zig-zag ridges on Mars
Click for full image.
Cool image time! The photo to the right, cropped and reduced to post here, was taken on April 9, 2022v by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a series of parallel zig-zag ridges in a flat, knobby terrain.
I don’t presume to explain this at all. According to one research paper,
This interplana region consists of extensive networks of ridges—the eponymous Aeolis Dorsa—and is interpreted as having formed by topographic inversion of fluvial and alluvial deposits.
Why these ridges zig-zag however does not seem to fit into either a fluvial or alluvial explanation, both of which involve the flow of water. The quote implies these could be inverted stream channels (where the compacted streambed becomes a ridge when the surrounding terrain erodes away), but once again, the distinct zig-zag pattern seems wrong. Rivers meander, but they don’t generally turn right and left so sharply. And why should we see parallel zig-zags? This doesn’t seem to fit with a river channel origin.
The particular location, as shown on the overview map below, is close to the dry Martian equator, on the edge of Medusae Fossae Formation, the largest field of volcanic ash dust on Mars.
The white dot about 500 miles to the east of Curiosity marks the location of these zig-zag ridges. The proximity of Medusae, with its vast supply of dust, makes me wonder if we are looking at some form of dune, now hardened and eroded many eons after its formation.
This is however a guess, and should not be taken at all seriously. The suggestion in the science paper above is far more likely. For example, if these are inverted river channels, erosion over eons could have caused the meanders to sharpen into these abrupt turns.
Then again, I remain skeptical. I wonder also if we are looking at extrusions through faults, caused by volcanic activity.
Ah, the wonder of the universe. It is so much fun to attempt to untangle its mysteries.
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 print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit.
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 photo to the right, cropped and reduced to post here, was taken on April 9, 2022v by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a series of parallel zig-zag ridges in a flat, knobby terrain.
I don’t presume to explain this at all. According to one research paper,
This interplana region consists of extensive networks of ridges—the eponymous Aeolis Dorsa—and is interpreted as having formed by topographic inversion of fluvial and alluvial deposits.
Why these ridges zig-zag however does not seem to fit into either a fluvial or alluvial explanation, both of which involve the flow of water. The quote implies these could be inverted stream channels (where the compacted streambed becomes a ridge when the surrounding terrain erodes away), but once again, the distinct zig-zag pattern seems wrong. Rivers meander, but they don’t generally turn right and left so sharply. And why should we see parallel zig-zags? This doesn’t seem to fit with a river channel origin.
The particular location, as shown on the overview map below, is close to the dry Martian equator, on the edge of Medusae Fossae Formation, the largest field of volcanic ash dust on Mars.
The white dot about 500 miles to the east of Curiosity marks the location of these zig-zag ridges. The proximity of Medusae, with its vast supply of dust, makes me wonder if we are looking at some form of dune, now hardened and eroded many eons after its formation.
This is however a guess, and should not be taken at all seriously. The suggestion in the science paper above is far more likely. For example, if these are inverted river channels, erosion over eons could have caused the meanders to sharpen into these abrupt turns.
Then again, I remain skeptical. I wonder also if we are looking at extrusions through faults, caused by volcanic activity.
Ah, the wonder of the universe. It is so much fun to attempt to untangle its mysteries.
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 print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit. 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
Reminds me of wind formed sand dunes.
Zigzags roughly evenly spaced crest to crest. Zigzag vertices roughly evenly spaced.
Crest heights diminish in a singular direction due to local topography/obstruction distribution changes.
Guessing, of course.