A planet is a planet wherever it resides, right? Dave Eicher examines the case of the icy world.In 1930 a young astronomer from Kansas, employed as an observer at Lowell Observatory in Arizona, discovered Pluto. It was the first planet in the solar system to have been discovered since 1846, when astronomers in Germany detected Neptune. Clyde Tombaugh, just 24 at the time, was hailed as a hero, Disney named a cartoon dog after the new planet, and for 76 years the solar system was a happy place. And then, in 2006, the International Astronomical Union (IAU) reconsidered Pluto’s status....