50,000 years ago, an unbroken plain stretched out endlessly.  Suddenly, out of the northeastern sky, a pinpoint of light grew rapidly into a brilliant meteor.  Hurtling at about 40,000 miles per hour, in microseconds it passed through the atmosphere with almost no loss of velocity or mass.  In a blinding flash a huge iron-nickel meteorite or dense cluster of meteorites, estimated to have been about 150 feet across and weighing several hundred thousand tons, struck the once flat plain with an explosive force greater than 20 million tons of TNT.

In the air, shock waves swept across the level plain devastating all in their path for miles.  In the ground, pressure rose to over 20 million pounds per square inch, and both iron and rock experienced vaporization and extensive melting.  Beyond the melted region, an enormous volume of rock underwent complete fragmentation and ejection.

The end result was the excavation of a bowl-shaped cavity.  In less than a few seconds, a crater 700 feet deep and over 4000 feet across was carved into the flat plain of Arizona.  Over 175 million tons of limestone and sandstone were thrown out to form a continuous blanket of debris surrounding the crater for a distance of over one mile.  Limestone the size of houses were heaved onto the rim of the crater.  Fragments of rock and iron-nickel were thrown several miles into the distance.  Intense pressure transformed small concentrations of graphite into diamonds.

The topographical terrain of Meteor Crater so closely resembles that of the Earth's moon and other planets, NASA designated it one of the official training sites for the Apollo Astronauts.  The pictures below (click on them for a larger view) provide you with on-site visual images.  For further information or to visit the official site, click here.