First predicted in the 1840s by the French astronomer Urbain le Verrier, the planet Pluto wasn’t located and identified for almost a hundred years. American astronomer Percival Lowell took it upon himself and his observatory to find the planet that was predicted using Newtonian mechanics and the perturbations of the planet Neptune. Lowell threw resources at the problem for over a decade, actually imaging the planet in 1915 but not recognizing it. His death slowed the project for a decade until 23 year old Kansas native Clyde Tomsbaugh began searching again in earnest, finally identifying it February 1930. It was a huge international scientific sensation, and a search for a name began. 11 year old Venetia Burney from Oxford England suggested the name Pluto through her grandfather (a librarian at the Bodleian Library) who passed it along to colleagues at the Observatory. Pluto, the ruler of the Greek Underworld, was a shadowy and nearly invisible figure-much like the planet. Although they received over 1,000 suggestions, only three made the final vote: Pluto, Minerva and Cronus. Minerva was already the name of an asteroid and Pluto received all the votes. Pluto was named May 1, 1930.
Pluto has four moons, Chiron, discovered in 1978 by astronomer James Christy; Nix and Hydra, both discovered by the Hubble team in 2005, and P4, an unnamed moon discovered in 2011 and not yet named.
In 2006 the International Astronomical Union created a controversy by developing a system of criteria for planets that mean Pluto was inelible for the distinction and was relegated to ‘dwarf planet’ status. There were world wide objections, both in the scientific community and in the culture at large, culminating in a meeting at Johns Hopkins University that led to the designation of plutoids.
Venetia died April 30, 2009 after a long career as an educator.
Image of Pluto and its moons courtesy NASA/Hubble. Image of Venetia Burney courtesy of the BBC, now in the public domain.