Discovery of Nix and Hydra Moons

Date: October 31, 2005 • Location: Rome, Italy

The discovery of the Plutonian moons Nix and Hydra, based on photographs taken by the Hubble Space Telescope nearly five months prior, was announced.

There are five known moons of the dwarf planet Pluto. In order of distance from Pluto, they are Charon, Styx, Nix, Kerberos, and Hydra. Charon, the largest, is mutually tidally locked with Pluto, and is massive enough that Pluto and Charon are sometimes considered a binary dwarf planet.