The second dwarf planet found in the Kuiper Belt, briefly referred to as the 10th planet. Being more massive than Pluto and about the same size, Eris' discovery lead to a new definition of the word planet and reclassified itself, Pluto, and Ceres and Dwarf Planets. Originally designated 2003 UB313 and codenamed "Xena", it is now named after the Greek goddess of discord. Furthest body detected at time of discovery, when it was near its aphelion, nearly three times as far as Pluto. Much more dense than Pluto (and thus composed of more rock) and further away, but has about the same surface composition. Largest scattered disc object, which depending on the definition used, would also be the largest Kuiper Belt object. Color appears greyish, unlike Pluto, because it is far enough for Methane to condense on all parts of its surface, including low albedo features. Like Pluto, and unlike other large KBOs, it has Methane on its surface. Currently has no atmosphere. Its albedo is greater than freshly fallen snow, and one of the most reflective known objects in the Solar System. Has one small moon, Dysnomia, which allowed its mass to be computed as a 27% greater than Pluto's. Its size became better known than Pluto's temporarily in 2011, at 2326 km +/- 12 km, but was found to be slightly smaller when Pluto's size was remeasured. Its atmosphere may return when it gets closer, possibly revealing a patchy surface like Pluto's.