Pluto's 248-Year Orbit Reaches Its First Lap in 2178
Pluto's year is about 248 Earth years, so since its 1930 discovery it has not completed a full orbit and will not until March 23, 2178. Its highly elliptical, inclined orbit takes it between 30 and 49 AU from the Sun, with perihelion in 1989 and aphelion around 2114. Pluto was reclassified as a dwarf planet in 2006, and NASA's New Horizons carried Clyde Tombaugh's ashes on its 2015 Pluto flyby.