From where do Pluto and its moons get their mythological names?

Answer 1

Pluto is the Roman name of the god Hades, the god of the underworld. It follows the tradition of naming the planets after the Greek and Roman gods. Charon* was the Greek name of the boatman who ferried souls to Hades. Nix was the Greek goddess of darkness and night (paradoxically, Charon's mother). Hydra was the Greek or Roman serpent guarding the entrance to the underworld. *actually adopted by one of the discoverers as similar to his wife's name. Normally pronounced "SHAH-run" in the US and "KAH-run" elsewhere.