Meteor Crater is one of the youngest and best-preserved impact craters on Earth. The crater formed roughly 50,000 years ago when a 30-meter-wide, iron-rich meteor weighing 100,000 tons struck the Arizona desert at an estimated 20 kilometers per second. The resulting explosion exceeded the combined force of today's nuclear arsenals and created a 1.1-kilometer-wide, 200-meter-deep crater. Meteor Crater is a simple crater since it has no central peak or rim terraces.
PHOTO: D. Roddy/U.S. Geological Survey/NASA