c tombaugh


Clyde William, 1906–97, U.S. astronomer: discovered Pluto 1930.
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World English Dictionary
Tombaugh (ˈtɒmbəʊ)
Clyde William. 1906--97, US astronomer, who discovered (1930) the dwarf planet Pluto

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American Heritage
Science Dictionary
Tombaugh   (tŏm'bô')  Pronunciation Key 
American astronomer who discovered the planet Pluto in 1930. The existence of an outermost planet, known as Planet X, had been predicted some years earlier by the American astronomer Percival Lowell based on apparent perturbations in the orbits of Neptune and Uranus. Tombaugh's careful analysis of celestial photographs did reveal a new planetary body, although it was too small to have caused the perturbations. Planet X itself was never found.
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