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
Greek mythology Petrarch, Boccaccio and Dante in Italy. In Northern Europe, Greek mythology never took the same hold of the visual arts, but its effect was very obvious on literature. The English imagination was fired by Greek mythology starting with Chaucer and John Milton and continuing through Shakespeare to Robert Bridges in the 20th century. Racine in France and Goethe in Germany revived Greek drama, reworking the ancient myths. Although during the Enlightenment of the 18th century reaction against Greek myth spread throughout Europe, the myths continued to provide an important source of raw material for dramatists, including those who wrote the