A Closer Look: Meteorites

A meteoroid is matter in interplanetary space that is too small to be called an asteroid or a comet but too large to be classified as cosmic dust grains. A meteorite is a meteoroid that reaches the surface of the Earth without being completely destroyed by its passage through Earth's atmosphere.
There are two kinds of places on Earth where meteorites are more likely to be found. One is on parts of the Antarctic ice cap where the ice flows together and evaporates in the sun and wind, leaving behind meteorites as a lag deposit. The other prime meteorite hunting ground is in deserts, where the dry conditions tend to preserve stones and the lack of rain means they are less likely to wash away.

Almost all meteorites come from the asteroid belt between Mars and Jupiter, where thousands of small, solid objects orbit the Sun. Some meteorites show geochemical signs of having been part of an evolving planet. Some are similar to basaltic rocks found on Earth. These basaltic meteorites are created by the impacts of other meteorites onto other bodies in the solar system, most commonly Mars and the Moon.

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