From 1930 (when it was discovered) until 2006 (when it was reclassified as a dwarf planet), Pluto was the furthest planet from the sun in our solar system. Smaller than the Earth’s Moon (about two-thirds the diameter) and with three moons (Chraron, Hydra and Nix) of its own, Pluto is now thought of as a member of the group of objects (beyond the orbit of Neptune, now the furthest planet from the sun in our solar system) called the Kuiper Belt.
The NASA “Solar System Exploration” site has an excellent section on Pluto. The NASA site includes facts about Pluto, links to other excellent resources about Pluto, and an image gallery. You will also find a link to information about the New Horizons Mission; The New Horizons spacecraft has been designed to “…make the first close-up study of Pluto and its moons and other icy worlds in the distant Kuiper Belt. The spacecraft has seven scientific instruments to study the atmospheres, surfaces, interiors and intriguing evnironments of Pluto and its distant neighbors.” This is the first mission to Pluto and the Kuiper Belt. Launched in January 2006, New Horizons is scheduled to reach Pluto in 2015.
If you can’t wait until 2015 for more information about Pluto, you might be interested in the following books at the Kresge Library:
- Mike Brown (2010), “How I killed Pluto and why it had it coming”
- Barrie William Jones (2010), “Pluto: Sentinel of the Outer Solar System”
- Neil deGrasse Tyson (2009), “The Pluto Files: The Rise and Fall of America’s Favorite Planet”
- David A. Weintraub (2007), “Is Pluto A Planet? : A Historical Journey Through the Solar System”