Changing slope streaks on Mars
Click for full image.
Cool image time! The photo to the right, cropped and reduced to post here, was taken on July 20, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists have labeled a “Splitting Slope Streak” on a mound/hill near the equator and located almost midpoint between the giant volcano Olympus Mons about 2,000 miles to the east and the almost as big volcano Elysium Mons about 2,500 miles to the west. The white cross on the overview map above marks this location, north of the Medusae Fossae volcanic ash deposit.
The slope streak in question is the biggest and darkest at about 7 o’clock. Slope streaks are a feature unique to Mars that remain as yet unexplained. They are not ordinary avalanches, despite their appearance. They seem to have no effect on the topography, and thus are more a stain on the surface. Moreover, some are bright, some dark, and all happen randomly and fade with time. Some think they may be brine-related, while others link them to dust. No theory explains them completely.
What makes this slope streak interesting is that it is relatively new. Compare it with the picture taken in 2016 below.
Click for full image.
Because MRO’s high resolution camera has not photographed this mound as yet, the picture to the right comes from its context camera, which takes wide survey images of less resolution. I have cropped and reduced the image, taken in September 2016, to match the high resolution photo above.
Note how the older streaks have faded in the six years since 2016. The newer streaks in the 2022 picture meanwhile are all dark, with the largest and darkest new streak apparently splitting to go around an older and very faded earlier streak.
Why? Why should a newer streak avoid the surface of an earlier streak? Since the cause of slope streaks remains unresolved, this behavior only adds to the puzzle, though it might also provide researchers a new data point for solving the mystery itself.
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 photo to the right, cropped and reduced to post here, was taken on July 20, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists have labeled a “Splitting Slope Streak” on a mound/hill near the equator and located almost midpoint between the giant volcano Olympus Mons about 2,000 miles to the east and the almost as big volcano Elysium Mons about 2,500 miles to the west. The white cross on the overview map above marks this location, north of the Medusae Fossae volcanic ash deposit.
The slope streak in question is the biggest and darkest at about 7 o’clock. Slope streaks are a feature unique to Mars that remain as yet unexplained. They are not ordinary avalanches, despite their appearance. They seem to have no effect on the topography, and thus are more a stain on the surface. Moreover, some are bright, some dark, and all happen randomly and fade with time. Some think they may be brine-related, while others link them to dust. No theory explains them completely.
What makes this slope streak interesting is that it is relatively new. Compare it with the picture taken in 2016 below.
Click for full image.
Because MRO’s high resolution camera has not photographed this mound as yet, the picture to the right comes from its context camera, which takes wide survey images of less resolution. I have cropped and reduced the image, taken in September 2016, to match the high resolution photo above.
Note how the older streaks have faded in the six years since 2016. The newer streaks in the 2022 picture meanwhile are all dark, with the largest and darkest new streak apparently splitting to go around an older and very faded earlier streak.
Why? Why should a newer streak avoid the surface of an earlier streak? Since the cause of slope streaks remains unresolved, this behavior only adds to the puzzle, though it might also provide researchers a new data point for solving the mystery itself.
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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