Persephone, commonly called Rupert, was a planet somewhere in Sol's outer solar system, either in the Kuiper Belt or even as far away as the Scattered disk. It was situated past Pluto in relation to distance from the sun. Persephone was settled by the Grebulons. The planet's nickname Rupert comes from the name of the parrot of the astronomer who found the planet.

Appearances

The Douglas Adams novel Mostly Harmless .

. The Quintessential Phase of the radio series

Trivia