Dis Pater, Orcus, and the Modern Planet

At Rome the same god was worshipped as Dis Pater, a direct Latin translation, dis being a contraction of dives, rich, and identified with an older Italic death-god, Orcus, whose name survives in Italian orco and, at a distance, in the English ogre. In 249 BCE the Romans instituted nocturnal sacrifices to Dis Pater and Proserpina at an altar in the Campus Martius as part of the games later known as the Secular Games. The name found a modern afterlife in 1930 when the newly discovered ninth planet was named Pluto, a choice that pleased its backers partly because its first two letters were the initials of Percival Lowell, so that the Roman lord of the hidden depths gave his name to the most distant and shadowed body then known.

Medieval readers frequently blurred Pluto with a distinct Greek deity of similar name, Plutus, the personified god of wealth and abundance who appears in Aristophanes and Hesiod; Dante's Inferno places a demon called Pluto, drawn from Plutus, guarding the fourth circle of the avaricious and the wasteful, a conflation later scholars have traced to the two names' near-identity in Latin translation and to Pluto's own ancient reputation, sketched already at Eleusis, as a giver of the earth's riches rather than merely their lord below. The confusion persisted into Renaissance mythography before philologists began to separate the two figures more carefully.