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An artist's conception of Pluto, for the Pluto Fast Flyby Mission.
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Image courtesy of NASA/JPL. This image is in the public domain.

Pluto

Pluto is a frigid ball of ice and rock that orbits far from the Sun on the frozen fringes of our Solar System. Considered a planet, though a rather odd one, from its discovery in 1930 until 2006, it was officially stripped of its status as our Solar System's 9th planet by the International Astronomical Union in August 2006.

Pluto is now officially classified as a dwarf planet. It is one of the largest members of a class of icy spheres known as Kuiper Belt Objects. It has known moons; one of which, Charon, is very large - almost as big as Pluto itself!

The surface of Pluto appears to be composed of a mixture of ice and rock, while its interior is probably similar to that of other icy moons in the solar system. Surprisingly, Pluto does have an atmosphere which is continuously produced and lost while Pluto is within Neptune's orbit. No one knows yet if Pluto has a magnetosphere or not! Maybe we will find out when NASA's New Horizon mission, which launched in 2006, makes it to Pluto in 2015!

In the Roman pantheon, Pluto was the god of the underworld, and the husband of the beautiful but ill-fated Persephone.

Last modified August 25, 2006 by Randy Russell.

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