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
Ino (Greek mythology) at Magnesia (Burkert 1992:44). Ino (Greek mythology) In Greek mythology Ino (; Ancient Greek: Ἰνώ, ) was a mortal queen of Boeotia, who after her death and transfiguration was worshiped as a goddess under her epithet Leucothea, the "white goddess." Alcman called her "Queen of the Sea" (), which, if not hyperbole, would make her a doublet of Amphitrite. Ino was the second wife of the Minyan king Athamas, mother of Learches and Melicertes and stepmother of Phrixus and Helle. She was the second daughter of Cadmus and Harmonia and one of the three sisters of Semele, the mortal woman