Glossary of Scientific Terms

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Pluto

A computer enhanced image of Pluto made from Hubble Space Telescope images taken in 1994.

Typically orbiting the sun beyond the orbit of Nuptune, Pluto is a dwarf planet and takes 248 years to orbit the sun once. Pluto is about 5.5 times smaller than the Earth and is about 450 times less massive. Pluto was discovered on February 18, 1930 by Clyde Tombaugh. Although it was once classified as a planet, Pluto lost this distinction on August 24, 2006.

In Greek mythology, Pluto is another name for Hades, the king of the underworld. Pluto was the son of Cronus and Rhea.

Planetary Data

Distance from SunLength of DayLength of YearRadiusMass
39.48 AU153.3 days247.92 years1,195 km1.3*1022 kg

Known Satellites

NameDistance from PlutoRotational PeriodOrbital PeriodRadius
Charon19,600 km-unknown-6.38725 days593 km
Hydra-unknown--unknown--unknown--unknown-
Nix-unknown--unknown--unknown--unknown-

Planetary and Satellite Data: NASA's Solar System Explorer