As a Delta Air Lines jet was flying over Arizona on a clear day, the co-pilot was providing his passengers with a running commentary about landmarks over the PA system. "Coming up on the right, you can see the Meteor Crater, which is a major tourist attraction in northern Arizona. It was formed when a lump of nickel and iron, roughly 150 feet in diameter and weighing 300,000 tons, struck the earth at about 40,000 miles an hour, scattering white-hot debris for miles in every direction. The hole measures nearly a mile across and is 570 feet deep." From the cabin, a passenger was heard to exclaim, "Wow! It just missed the highway!"