Moons of Pluto Moons of Pluto The dwarf planet Pluto has five moons down to a detection limit of about 1 km in diameter. In order of distance from Pluto, they are Charon, Styx, Nix, Kerberos, and Hydra. Charon, the largest of the five moons, is mutually tidally locked with Pluto, and is massive enough that Pluto–Charon is sometimes considered a double dwarf planet. The innermost and largest moon, Charon, was discovered by James Christy on 22 June 1978, nearly half a century after Pluto was discovered. This led to a substantial revision in estimates of Pluto's size, which had previously assumed that
The Pluto Files The Pluto Files The Pluto Files: The Rise and Fall of America's Favorite Planet is a book written by the astrophysicist and Hayden Planetarium director Neil deGrasse Tyson. The book is about Pluto, which was demoted to the status of dwarf planet in August 2006 by the International Astronomical Union, thereby depriving it of its planet-hood. The book also focuses on the fact that many Americans rallied their support for this icy dwarf on the edge of the Solar System because it was discovered by an American. The book was given a good review by Jon Stewart in a guest