A region of the solar system beyond the orbit of Neptune, some 30Ã¢ÂÂ1000 astronomical units from the sun, containing up to one thousand million icy planetesimals or comet nuclei
United States astronomer (born in the Netherlands) who studied the solar system and suggested in 1951 that there is a belt of comet-like debris at the edge of the solar system (1905-1973)
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WordNet. Princeton University. 2010.