1. An interplanetary material or a meteoroid that survives passage through the earth's atmosphere and arrives on earth's surface without completely burning up.
2. A piece of rock or metal from space that reaches the surface of the earth, moon, or other celestial body.

Most meteorites are thought to be fragments from asteroids, although some may be pieces from the heads of comets. Most are stony, although some are made of iron and a few have a mixed rock-iron composition.