Discusses the differences between comets, asteroids, and meteoroids, their composition, their origins, and their place in the solar system.

The beginning of the solar system -- Comets: dirty balls of ice -- Comets: a long journey -- Asteroids: minor planets -- Asteroids: where they orbit -- Meteoroids and meteors: rock from space to earth -- Meteorites: hitting earth's surface -- Studying the solar system -- Our solar system.