What happens to a meteor when it hits the ground?

For small meteors, they reach a terminal speed of only a few hundred miles per hour, and by the time they reach ground they are cool to the touch. Large ones as big as a baseball or even a small car, will leave pits about as big as they are. Very large bodies a few yards across may leave craters hundreds of yards cross. They may be pulverized upon impact so that all that remains near or in the crater are fragments a few inches across. There may, or may not, be large chunks left over depending on the composition of the meteor. For the Barringer Crater in Arizona, only small fragments of a large body perhaps a hundred yards across, is all that survives. The impact energy can be high enough to cause fires due to the frictional energy shed by the body.

Most of the energy can propel lots of ground into the air, which rains down upon the surroundings in a thick blanket of heated, even molten, rock. Tektites are probably produced this way, although some experts also consider the Moon as a possible secondary source. This requires truly spectacular impacts of kilometer-sized bodies. There are only four known tektite fields on Earth: North America (33 million years), Czechoslovakia (15 million years), Ivory Coast (1 million years) and Southeast Asia/Australia (700,000 years or less).

This answer was updated in 2011. See my books: The Astronomy Cafe (1998) and Back to the Astronomy Cafe (2003) for more FAQs in printed form. Author: Dr. Sten Odenwald, Copyright 2011

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