Pluto and the Kuiper Belt
Image: NASA |
Amazing fact!
Some astronomers think there is another planet beyond even Pluto, hiding somewhere in the Kuiper Belt or Oort Cloud. This mysterious ‘planet X’ could be responsible for disturbing the orbits of some comets and the outer planets. |
Poor old Pluto – it used to be a planet, but in 2006 astronomers voted to reclassify it to dwarf planet status because Pluto is too small to be a proper planet. Pluto is part of a collection of small icy worlds on the edge of our Solar System that we call the Kuiper (pronounced Koy-per) Belt. The Kuiper Belt also includes the other dwarf planet Eris (which is actually bigger than Pluto, has one moon, and is a recent addition to the Solar System family having been discovered in 2005 by Michael Brown), and smaller objects such as Sedna and Quaoar (pronounced Kwa-war). Beyond the Kuiper Belt is the Oort Cloud, a huge region of icy objects that stretch a quarter of the way to the nearest star, and from where comets come from.
Pluto, which was discovered in 1930 by the American astronomer Clyde Tombaugh, has three moons. The largest is called Charon, and Pluto and Charon always point the same face to each other, like Earth and the Moon. Two other small moons, called Nix and Hydra, were discovered in 2005. Pluto has yet to be visited by a spacecraft from Earth, but that won’t be the case for much longer – a NASA spacecraft is on its way now, and will get there in the year 2015. Mark your diaries!
Left: Pluto and its moons Charon, Hydra and Nix; Right: Eris and its moon Dysnomia.
Image: IAU.
SUN MERCURY VENUS EARTH MARS ASTEROID BELT JUPITER SATURN URANUS NEPTUNE PLUTO
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