METEORITE
A
METEORITE is a
small extraterrestrial
body that impacts the Earth's surface. While in space they are called meteoroids, and while falling through Earth's atmosphere they are called meteors. These are small asteroids, approximately boulder-sized or less. When it enters the atmosphere, air resistance causes the body to heat up and emit light, thus forming a fireball or shooting star.
More generally, a meteorite on a celestial body is a small body that has come from elsewhere in space. The only example of a meteorite that didn't fall on Earth is the Heat Shield Rock, which was found on Mars.
Meteorites are classified according to their structure and mineral composition. The three main classes of meteorite are
stony, stony-
iron and iron.
One theory suggests that a large meteorite impact caused the
mass extinction of the dinosaurs. It is also theorized that meteorites caused other mass extinction events throughout the history of the Earth.