Neil deGrasse Tyson didn’t mean to get Pluto demoted from planet status; he just wanted people to think about the solar system differently. But changing the number of planets from nine to eight is just what happened when a debate sparked by the astrophysicist’s Hayden Planetarium exhibit – sans Pluto – ended with the re-categorization of the icy rock to “dwarf planet” status. Dr. Tyson tells his story – and the story of Pluto – in his new book “The Pluto Files: The Rise and Fall of America’s Favorite Planet.” He talks with host Steve Curwood.