You can learn more about the discovery of Sedna at www.gps.caltech.edu/~mbrown/sedna/ and www.spitzer.caltech.edu/Media/releases/ssc2004-05/ (California Institute of Technology).
Information about the New Horizons spacecraft is available at pluto.jhuapl.edu/
(Johns Hopkins University Applied Physics Laboratory).
You can take a multimedia tour of the solar system at www.nineplanets.org/(Bill Arnett).
Cowen, Ron. 2004. Planetoid on the fringe: Solar system record breaker. Science News 165(March 20):179. Available at http://www.sciencenews.org/articles/20040320/fob1.asp.
Sohn, Emily. 2003. Sky dust keeps falling on your head. Science News for Kids (Aug. 13). Available at http://www.sciencenewsforkids.org/2003/08/sky-dust-keeps-falling-on-your-head-2/.
Hubble Space Telescope A satellite that orbits the Earth and carries a very powerful telescope for observing objects throughout the universe. The Hubble Space Telescope goes around the Earth every 97 minutes. It has taken hundreds of thousands of pictures of objects in outer space.
Kuiper belt A region in the outer Solar System that contains thousands of small, icy objects.
Oort cloud A group of more than 100 billion comets that makes up the outer edge of the Solar System. The Oort cloud surrounds the planets and the region of icy objects known as the Kuiper belt.
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