Hydra (moon) the Hydra, the nine-headed serpent that battled Heracles in Greek mythology. The nine heads of Hydra are a reference to Pluto's tenure as the ninth planet; its initial, "H", refers to the Hubble Telescope, which discovered Hydra and, together with Nix, to the "New Horizons" mission whose safe passage was the motivation for taking the Hubble images. Hydra orbits the barycenter of the system in the same plane as Charon and Nix, at a distance of about 65,000 km. Its eccentricity of 0.0059 is small, but significantly non-zero, and the largest of those of Pluto's small moons (slightly larger than
Pygmy (Greek mythology) Pygmy (Greek mythology) The Pygmies ( "Pygmaioi", from the adjective πυγμαῖος from πυγμή "pygmē", "the length of the forearm") were a tribe of diminutive humans in Greek mythology. According to the Iliad, they were involved in a constant war with the cranes, which migrated in winter to their homeland on the southern shores of the earth-encircling river Oceanus. One story describes the origin of the age-old battle, speaking of a Pygmy Queen named Gerana who offended the goddess Hera with her boasts of superior beauty, and was transformed into a crane. In art the scene was popular with little Pygmies