Planetarium Show: the Case of the Disappearing Planet, Fresno Downing Planetarium September 25, 2010

Join Detective Skye Watcher as she examines the changing status of objects we call "planets." What exactly makes an object a planet? Why has that definition changed over the years? The program not only covers Pluto, but the temporary planetary status of asteroids as well. The tally of "planets" in our Solar System has been going up and down for hundreds of years!