The Colony Planets of Skaro were a group of seven "satellites" which surrounded Skaro and guarded it against invasion during the 27th century Dalek invasion.
Unispace once investigated the Colony Planets. Due to the "Planets" being so close to Skaro, the Unispace ships were caught in a Magnetrap and pulled to Skaro's surface. (PROSE: Manhunt [+]Loading...["Manhunt (short story)"])