Kuiper Belt
From Tardis Wiki, the free Doctor Who reference
The Kuiper Belt was a belt of rocks beyond the orbit of Neptune in the Solar System. It was discovered by Earth astronomers in 1992. It was very old, and was composed of the rocks that didn't form into planets or moons.
The Fourth Doctor and Sarah Jane Smith visited a spacecraft that was stationed in the Kuiper Belt. (PROSE: Observer Effect)
