Barringer Meteor Crater in Arizona

A meteor 50,000 years ago made this 1.2 km (3/4 mile) diameter crater in the Arizona desert. It left rare minerals that could only have been formed by the extreme pressure of such an event. While fragments of it have been recovered, the bulk of it may remain buried under the crater. This crater is the first crater on Earth to be firmly identified as due to an extraterrestrial impact. It exposes rocks over 250 million years old.

NASA trained its lunar astronauts here, and you can take virtual tour inside the crater with Google Map's Streetview