Scientists link near Earth asteroids Bennu and Ryugu to much larger main belt asteroid

Scientists comparing the spectroscopy of samples returned from the near Earth asteroids Bennu and Ryugu have found they closely resemble the much larger main belt asteroid Polana, suggesting all three formed at the same time and place.
You can read the paper here [pdf] From the press release:
The study compared spectroscopy data from Polana with spacecraft and laboratory data from Bennu and Ryugu samples, discovering similarities in their near-infrared spectrum sufficient to support the theory that they originate from the same parent asteroid. “Very early in the formation of the solar system, we believe large asteroids collided and broke into pieces to form an ‘asteroid family’ with Polana as the largest remaining body,” said SwRI’s Dr. Anicia Arredondo, lead author of the study. “Theories suggest that remnants of that collision not only created Polana, but also Bennu and Ryugu as well.”
While the similarities are great, the paper notes there are differences, possibly from “space weathering, particle size, surface texture, or different compositions.” The scientists believe the differences were caused by the asteroids’ different environments, with the 33-mile-wide and much older Polana in the asteroid belt beyond Mars, and Ryugu and Bennu, both less than a mile wide, orbiting the Sun inside Mars.
It is also possible the asteroids have little to do with each other, and the similar spectroscopy only informs us of some of the more common components of the early solar system.
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
Scientists comparing the spectroscopy of samples returned from the near Earth asteroids Bennu and Ryugu have found they closely resemble the much larger main belt asteroid Polana, suggesting all three formed at the same time and place.
You can read the paper here [pdf] From the press release:
The study compared spectroscopy data from Polana with spacecraft and laboratory data from Bennu and Ryugu samples, discovering similarities in their near-infrared spectrum sufficient to support the theory that they originate from the same parent asteroid. “Very early in the formation of the solar system, we believe large asteroids collided and broke into pieces to form an ‘asteroid family’ with Polana as the largest remaining body,” said SwRI’s Dr. Anicia Arredondo, lead author of the study. “Theories suggest that remnants of that collision not only created Polana, but also Bennu and Ryugu as well.”
While the similarities are great, the paper notes there are differences, possibly from “space weathering, particle size, surface texture, or different compositions.” The scientists believe the differences were caused by the asteroids’ different environments, with the 33-mile-wide and much older Polana in the asteroid belt beyond Mars, and Ryugu and Bennu, both less than a mile wide, orbiting the Sun inside Mars.
It is also possible the asteroids have little to do with each other, and the similar spectroscopy only informs us of some of the more common components of the early solar system.
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
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