Scientists: most asteroids come from a limited number of earlier break-ups
According to three different recently published papers (available here, here, and here), the majority of all meteorites hitting the Earth likely came from a limited number of specific past break-ups of larger asteroids.
New studies show that 70% of the 70,000 meteorites that have been found on Earth have come from 3 recent collisions in the main asteroid belt which sits between the orbits of Mars and Jupiter. The collisions occurred 5.8, 7.5 and 40 million years ago, according to the studies. They correspond to 3 young asteroid “families” known as Karin, Koronis and Massalia. These families formed from the destruction of asteroids at least 30km across.
The 70% number comes from data in the last two papers above, while the first paper claims it is more like 80% of all asteroids. The Massalia family is the most dominate, with it estimated to be the source 37% of all meteorites as well as a major impact half a billion years ago.
The first study also found that both Ryugu and Bennu came from the same event and are part of another family of asteroids called Polana.
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
According to three different recently published papers (available here, here, and here), the majority of all meteorites hitting the Earth likely came from a limited number of specific past break-ups of larger asteroids.
New studies show that 70% of the 70,000 meteorites that have been found on Earth have come from 3 recent collisions in the main asteroid belt which sits between the orbits of Mars and Jupiter. The collisions occurred 5.8, 7.5 and 40 million years ago, according to the studies. They correspond to 3 young asteroid “families” known as Karin, Koronis and Massalia. These families formed from the destruction of asteroids at least 30km across.
The 70% number comes from data in the last two papers above, while the first paper claims it is more like 80% of all asteroids. The Massalia family is the most dominate, with it estimated to be the source 37% of all meteorites as well as a major impact half a billion years ago.
The first study also found that both Ryugu and Bennu came from the same event and are part of another family of asteroids called Polana.
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