The long, bitter debate over Meteor Crater

Long before Arizona’s Meteor Crater got its name, scientists puzzled over its origin. Grove Gilbert, a well-respected figure at the US Geological Survey, thought a steam explosion had hollowed out the vast bowl of desert, while a scientific outsider named Daniel Barringer insisted that an impact had blasted it out. It took more than half a century and the discovery of a rare mineral to close the debate for good. Learn how in my story for EARTH Magazine.

Arizona's meteor crater, from above. (Credit: NASA)
Arizona’s meteor crater, from above. (Credit: NASA)