Pluto was discovered in 1930 by an American astronomer named Clyde Tombaugh. He found it while working at the Lowell Observatory in Arizona after carefully studying photographic plates of the night sky. At the time, scientists were searching for a mysterious “Planet X” that they believed existed beyond Neptune. Tombaugh’s discovery was a huge moment in astronomy and made Pluto famous worldwide. For decades after that, Pluto was considered the ninth planet in our solar system. It remained in that category until the scientific definition of a planet changed in 2006. Even today, the discovery of Pluto is seen as one of the most important achievements in space exploration history.
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