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
Battle of the Lerna Mills Battle of the Lerna Mills The Battle of the Lerna Mills was fought on June 24, 1825 in Lerna, Greece between the Egyptian forces of Ibrahim Pasha and Greek forces led by Captain Ioannis Makrygiannis, Demetrios Ypsilantis and Konstantinos Mavromichalis. After the Greek army (led by Theodoros Kolokotronis) fled to Karitena, Ibrahim's forces captured Tripolitsa, which was completely abandoned. Immediately afterwards, Ibrahim sent 5000 soldiers to the plains of Argos in order to seize Nafplion. When Ibrahim's forces reached the mills of Lerna on June 24, Captain Makrygiannis and Mavromichalis organized a resistance force containing 350 Greek soldiers (Walter Alison