Asteroids Bear Scars of Moon’s Violent Formation
Asteroids contain signs of the colossal collision that formed the moon.
Nearly 4.5 billion years ago, a colossal impact between Earth and a Mars-size planet triggered the formation of the moon. But the giant collision did more than put a familiar face in our sky, according to a study published Thursday in the journal Science: Fragments from the impact not only struck the asteroid belt, but appear to have left telltale scars behind on the asteroids.
“This was a tremendous event, one of the biggest collisions in the inner solar system,” says study author Bill Bottke of the Southwest Research Institute. “It should have produced a lot of debris that would have been thrown completely out of the Earth-moon system.”
By running simulations of the collision, the researchers determined that many large