Pluto

Pluto is the ninth and smallest of the traditional planets of the Solar system, though its status as a planet has been disputed in recent years. more...

It has an eccentric orbit that is highly inclined with respect to the other planets and takes it closer to the Sun than Neptune. It is also the smallest planet and indeed is smaller than several moons of other planets (see the list of solar system objects by radius). Pluto itself has a large moon named Charon; two small moons were discovered in 2005. The New Horizons spacecraft, which lifted off from Cape Canaveral, Florida on January 19, 2006, is expected to become the first spacecraft to fly by Pluto on July 14, 2015.

Due to its small size and unusual orbit, there has been well publicized debate regarding Pluto's classification as a major or as a minor planet, with increasing momentum for recognizing dual status. Pluto is one of the largest known members of the main Kuiper Belt; one scattered Kuiper Belt object, 2003 UB₃₁₃, has been found that is larger than Pluto.

Pluto's astronomical symbol is a P-L monogram, ♇. This represents both the first two letters of the name Pluto and the initials of Percival Lowell, who had searched extensively for a ninth planet and who had lent his name to the observatory that eventually discovered Pluto. (Another symbol sometimes used for Pluto is an astrological symbol and not an astronomical one. It resembles that of Neptune, ♆, but has a circle in place of the middle spoke of the trident.)

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