Asteroid

An asteroid is a chunk of rock in space, large compared to many things but small compared to planets and stars. They are similar to, but not to be confused with, comets and planetoids.

While many asteroids were barren and lifeless, some had life such as the Fire Trap, and its native Sycorax also fashioned starships out of other, smaller asteroids. (DW: The Christmas Invasion)

Other asteroids were centres of trade, such as one on which the rare metal Baloovium was sold. (DW: Army of Ghosts)

Artificial asteroids were also created by some races, and the Nestenes fashioned plastic asteroids, landing them on various planets to animate for an invasion of said planet. (DW: Spearhead from Space)