Pluto a planet's discovery story

Courtesy of Astro Leo's planets

Pluto's discovery story is not only an important part of Astronomy's history, it is also part of American history. It all started with Uranus, the 7th planet. In the early 1840's French mathematician Urbain Le Verrier predicted that there should be another celestial body perturbing the orbit of planet Uranus. The story of the discovery of Neptune then confirmed this prediction from Le Verrier. Further observations of Uranus later in the 19th century led to the speculation of yet another celestial body still perturbing Uranus.  Therefore in 1906, Percival Lowell from Boston Massachusetts, started a project in search for the 9th planet from the Lowell Observatory in Flagstaff, Arizona.  Lowell died without knowing that the observatory had imaged Pluto but had failed to recognize it.

The search for Pluto was put into hiatus until 1929, when Clyde Tombaugh a natural from Kansas, working at the Lowell Observatory finally found a moving object in photographic plates between the nights of Januray 23rd and Janurary 29th, 1930.  The results were sent to the Harvard Observatory on March 13, 1930 after confirming with a third exposure made before in January 21st.  The name's that went up for vote were Minerva, Cronus and Pluto.   Pluto received every vote!