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 in popular culture Fairy Book". In C. S. Lewis's retelling of Cupid and Psyche, "Till We Have Faces", the narrator is Psyche's sister. Roberta Gellis's "Shimmering Splendor" is a retelling of Cupid and Psyche. The Italian poet Dante Alighieri used characters from the legend of Troy in his Divine Comedy, placing the Greek heroes in hell to show his contempt for their actions. Poets of the Renaissance began to widely write about Greek mythology, and "elicited as much praise for borrowing or reworking" such material as they did for truly original work. The poet John Milton used figures from classical mythology to "further