As a Delta Air Lines jet was flying over Arizona on a clear day,
 the copilot 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!"