Aligned erosion lines of Perseverance Valley
The uncertainty of science: Last week, while I was flying to Israel, the Opportunity science team announced the discovery of strange aligned erosion lines, what they are calling stone stripes, in Perseverance Valley.
The ground texture seen in recent images from the rover resembles a smudged version of very distinctive stone stripes on some mountain slopes on Earth that result from repeated cycles of freezing and thawing of wet soil. But it might also be due to wind, downhill transport, other processes or a combination.
…On some slopes within the valley, the soil and gravel particles appear to have become organized into narrow rows or corrugations, parallel to the slope, alternating between rows with more gravel and rows with less.
The origin of the whole valley is uncertain. Rover-team scientists are analyzing various clues that suggest actions of water, wind or ice. They are also considering a range of possible explanations for the stripes, and remain uncertain about whether this texture results from processes of relatively modern Mars or a much older Mars.
For those who are regular readers of Behind the Black, you already knew about a variation of this discovery back in November 2017, from my regular rover updates. Then, they discovered aligned groves in the gravel that looked to me like slickensides, erosion patterns produced by glacial activity. The science team told me, however, that they were favoring wind, not ice, as a primary cause, though that conclusion was far from certain.
In the press release last week, they focused more on the aligned erosion patterns in the fine gravel that appear to align perpendicular to the slope. Though they think they have found a comparable Earth-based phenomenon that might explain these patterns, it appears that the science team remains just as unsure of their cause as they are for the rocks.
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 or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. 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
The uncertainty of science: Last week, while I was flying to Israel, the Opportunity science team announced the discovery of strange aligned erosion lines, what they are calling stone stripes, in Perseverance Valley.
The ground texture seen in recent images from the rover resembles a smudged version of very distinctive stone stripes on some mountain slopes on Earth that result from repeated cycles of freezing and thawing of wet soil. But it might also be due to wind, downhill transport, other processes or a combination.
…On some slopes within the valley, the soil and gravel particles appear to have become organized into narrow rows or corrugations, parallel to the slope, alternating between rows with more gravel and rows with less.
The origin of the whole valley is uncertain. Rover-team scientists are analyzing various clues that suggest actions of water, wind or ice. They are also considering a range of possible explanations for the stripes, and remain uncertain about whether this texture results from processes of relatively modern Mars or a much older Mars.
For those who are regular readers of Behind the Black, you already knew about a variation of this discovery back in November 2017, from my regular rover updates. Then, they discovered aligned groves in the gravel that looked to me like slickensides, erosion patterns produced by glacial activity. The science team told me, however, that they were favoring wind, not ice, as a primary cause, though that conclusion was far from certain.
In the press release last week, they focused more on the aligned erosion patterns in the fine gravel that appear to align perpendicular to the slope. Though they think they have found a comparable Earth-based phenomenon that might explain these patterns, it appears that the science team remains just as unsure of their cause as they are for the rocks.
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 or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. 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