re: #750 JamesTKirk

A meteorite is a chunk of rock from space which has collided with the Earth’s surface. Before it hit the Earth, but after it entered the Earth’s atmosphere, it was a meteor. Before that, when it was a free-falling rock in space, it was a meteoroid.

An asteroid is a chunk of rock, larger than a meteoroid, which is still in space and in its own orbit — generally between Mars and Jupiter.

An asteroid can become a meteoroid if it gets knocked out of its orbit and enters the path of a planet, like Earth (and becomes a meteor on entering the Earth’s atmosphere and a meteorite on impact). That can happen if it collides with other asteroids or other debris that crosses its orbit.