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Thursday, October 28, 2010

Photo: Pluto Not a Planet, Astronomers Rule


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An artist's image shows Pluto (center) and its large "moon" Charon (right) from the surface of one of Pluto's two smaller satellites. The other small moon can be seen on the far left.

Pluto is no longer a planet, according to a new definition of the term voted on by astronomers, because it does not dominate the neighborhood around its orbit. Charon is half the size of Pluto and orbits along with it; the eight true planets are all far larger than their moons.

Image courtesy NASA, ESA and G. Bacon (STScI)