Neil deGrasse Tyson talked about The Pluto Files: The Rise and Fall of America's Favorite Planet (W.W. Norton & Co.; January 26, 2009). He writes about the controversy over re-classifying Pluto as a comet. New York's American Museum of Natural History, where this talk was held, was the first public institution to adopt this position. Mr. deGrasse Tyson responded to questions from audience members following his remarks. Neil deGrasse Tyson is an astrophysicist with the American Museum of Natural History and director of the museum's Hayden Planetarium. He is also the host of the PBS series "NOVA ScienceNOW." His books include Death by Black Hole and The Sky is Not the Limit.