What Happened to Earth’s Ancient Craters?

Meteor Crater near Winslow, Ariz., one of just 190 confirmed craters on Earth.CreditCreditDaniel Slim/Agence France-Presse — Getty Images

Meteor Crater near Winslow, Ariz., one of just 190 confirmed craters on Earth.CreditCreditDaniel Slim/Agence France-Presse — Getty Images

The pace of space rocks pummeling Earth and the moon was relatively infrequent, but then doubled or tripled for unknown reasons, a new study finds. Read more…

Jennie Wadsworth