Clyde Tombaugh
American astronomer who discovered Pluto in 1930.
via Wikipedia: Planet Nine · see source
He continued Lowell's search for a hypothetical trans-Neptunian planet, which Percival Lowell had called Planet X. Using a blink comparator, Tombaugh noticed a moving object on February 18, 1930, using images taken the previous month. Pluto was soon determined to be too small to qualify as Lowell's Planet X.
- known_for
- Discovery of Pluto
Verified Timeline
Lore & Background
Clyde Tombaugh continued Percival Lowell's search for a hypothetical trans-Neptunian planet, which Lowell had called Planet X. Lowell had predicted the possible orbit and location of the planet and began an extensive search for it in 1906. Tombaugh, working at Lowell Observatory, used a blink comparator to examine photographic plates. On February 18, 1930, he noticed a moving object using images taken the previous month. However, Pluto was soon determined to be too small to qualify as Lowell's Planet X. After Voyager 2's flyby of Neptune in 1989, the difference between Uranus' predicted and observed orbit was determined to have been due to the use of a previously inaccurate mass of Neptune, not an undiscovered planet.
Reader's Guide
Clyde Tombaugh's discovery of Pluto in 1930 was the culmination of a search begun by Percival Lowell in 1906 for a hypothetical trans-Neptunian planet, which Lowell called Planet X. Tombaugh used a blink comparator to compare photographic plates and spotted a moving object on February 18, 1930, using images taken the previous month. However, Pluto was soon determined to be too small to qualify as Lowell's Planet X. Later, after Voyager 2's flyby of Neptune in 1989, the discrepancy in Uranus' orbit was explained by an inaccurate mass for Neptune, not an unknown planet. Tombaugh's work remains a key moment in the history of Solar System discovery.
Did You Know?
- Clyde Tombaugh discovered Pluto on February 18, 1930, using images taken the previous month.
- The name 'Pluto' was proposed by an 11-year-old English girl, Venetia Burney, and officially adopted on May 1, 1930.
- Pluto was soon determined to be too small to qualify as Percival Lowell's hypothetical Planet X.
- After Voyager 2's flyby of Neptune in 1989, the discrepancy in Uranus' orbit was explained by an inaccurate mass for Neptune, not an undiscovered planet.
Frequently Asked Questions
Who is Clyde Tombaugh?
Clyde William Tombaugh (1906–1997) was an American astronomer and telescope craftsman best remembered for identifying Pluto in 1930.
What did Clyde Tombaugh discover?
In 1930 he located the small, distant body we now call Pluto, which was then listed as the ninth planet and later recognized as the first known member of the Kuiper belt.
When was Clyde Tombaugh born and when did he die?
He was born on February 4, 1906, and died on January 17, 1997. Because he passed away nearly a decade before the 2006 IAU reclassification, he never saw Pluto officially demoted to dwarf-planet status.
Why is Clyde Tombaugh important in astronomy?
His find expanded the mapped Solar System beyond Neptune and, in hindsight, revealed the first object of the Kuiper belt, reshaping how astronomers think about the outer reaches of our planetary neighborhood.
What was Clyde Tombaugh's field and nationality?
Tombaugh worked in the field of astronomy and held American nationality; he was also a talented telescope builder, a skill that supported his observational research.
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