Perseverance scientists: First volcanics then water in Jezero Crater
On December 15th the Perseverance science team presented a summary of the rover’s first nine months exploring the floor of Jezero Crater, finding evidence first of volcanic lava activity followed by several periods where water covered the these same rocks.
“These rocks that we originally thought might be sedimentary rocks, these are in fact igneous [volcanic] rocks,” said Kelsey Moore at the California Institute of Technology (Caltech). “And even more excitingly, they’re not just igneous rocks – there’s more history to the story.”
The analysis of the rocks’ compositions revealed minerals that are generally produced by interactions between water and rock, as well as traces of two different salts that were probably left behind as salty water flowed through the cracks and pores in the volcanic rock.
The variety of minerals indicates that these rocks were probably underwater at least twice. “Two different types of liquid with two different types of chemistries points towards two different episodes of liquid water interaction,” said Eva Scheller, also at Caltech.
It seems strange that the scientists were surprised that Jezero Crater has a history of volcanic activity. Most craters when formed have what is called impact melt in their crater interior. The impact not only carves out the crater, the heat of impact melts the rock. Possibly the scientists expected such impact melt to be well buried and not accessible to Perseverance.
Regardless, this data will be used as the baseline for documenting the geological history of this region on Mars as Perseverance continues its journey across the floor of the crater, up onto the delta, and then out of the crater into the uplands beyond.
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
On December 15th the Perseverance science team presented a summary of the rover’s first nine months exploring the floor of Jezero Crater, finding evidence first of volcanic lava activity followed by several periods where water covered the these same rocks.
“These rocks that we originally thought might be sedimentary rocks, these are in fact igneous [volcanic] rocks,” said Kelsey Moore at the California Institute of Technology (Caltech). “And even more excitingly, they’re not just igneous rocks – there’s more history to the story.”
The analysis of the rocks’ compositions revealed minerals that are generally produced by interactions between water and rock, as well as traces of two different salts that were probably left behind as salty water flowed through the cracks and pores in the volcanic rock.
The variety of minerals indicates that these rocks were probably underwater at least twice. “Two different types of liquid with two different types of chemistries points towards two different episodes of liquid water interaction,” said Eva Scheller, also at Caltech.
It seems strange that the scientists were surprised that Jezero Crater has a history of volcanic activity. Most craters when formed have what is called impact melt in their crater interior. The impact not only carves out the crater, the heat of impact melts the rock. Possibly the scientists expected such impact melt to be well buried and not accessible to Perseverance.
Regardless, this data will be used as the baseline for documenting the geological history of this region on Mars as Perseverance continues its journey across the floor of the crater, up onto the delta, and then out of the crater into the uplands beyond.
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