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
Modern understanding of Greek mythology mythology to the still poorly understood pre-Hellenic societies of Greece, such as the Minoans and so-called Pelasgians. This is especially true in the case of chthonic deities and mother goddesses. Historians of religion were fascinated by a number of apparently ancient configurations of myth connencted with Crete: the god as bull — Zeus and Europa; Pasiphaë who yields to the bull and gives birth to the Minotaur; agrarian mysteries with a sacred marriage (Demeter's union with Iasion) etc. Crete, Mycenae, Pylos, Thebes and Orchomenus figure so large in later Greek mythology. For some, the three main generations of gods in