clyde william tombaugh


Clyde William, 1906–97, U.S. astronomer: discovered Pluto 1930. Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source Link To Clyde William Tombaugh
World English Dictionary
Tombaugh (ˈtɒmbəʊ)
Clyde William. 1906--97, US astronomer, who discovered (1930) the dwarf planet Pluto

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
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.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Encyclopedia Britannica

clyde william tombaugh

American astronomer who discovered Pluto in 1930 after a systematic search for a ninth planet instigated by the predictions of other astronomers. He also discovered several clusters of stars and galaxies, studied the apparent distribution of extragalactic nebulae, and made observations of the surfaces of Mars, Venus, Jupiter, Saturn, and the Moon

Learn more about Tombaugh, Clyde William with a free trial on

Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
Cite This Source
Copyright © 2014, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature