Eleventh planet term "planet" was redefined to exclude the new category of dwarf planets (just as some planets had earlier been recategorised as asteroids). In 2006 Pluto, Eris, Haumea, Makemake, and (in the inner Solar System) the asteroid Ceres were reclassified as dwarf planets. Eleventh planet Eleventh planet (of the Solar System) may refer to Vesta, the eleventh object to be named a planet, later to be reclassified as an asteroid; Uranus, the eleventh planet from the Sun upon Vesta's discovery, though this was quickly superseded by new discoveries; or Haumea, which would be the eleventh planet if the classification advocated by
Discovery and exploration of the Solar System yet another planet, "Planet X", must lie beyond Neptune. After his death, his Lowell Observatory conducted a search that ultimately led to Clyde Tombaugh's discovery of Pluto in 1930. Pluto was, however, found to be too small to have disrupted the orbits of the outer planets, and its discovery was therefore coincidental. Like Ceres, it was initially considered to be a planet, but after the discovery of many other similarly sized objects in its vicinity it was reclassified in 2006 as a dwarf planet by the IAU. In 1992, the first evidence of a planetary system other than our own