Most meteorites that have fallen upon our planet originated within the Asteroid Belt, which lies between Mars and the gas giant Jupiter. The vast majority of stone meteorites were once part of the crust of these asteroids. Cosmic collisions caused some of these wandering space nomads to break up, hurling fragments in different directions. Some of this debris crossed our planet's path, hitting the atmosphere at thousands of miles per hour, burning briefly in the cold, thin air and producing the spectacle we call meteors or shooting stars. Those that survive to land on the surface are known as meteorites.