The astrophysicist who got hate mail in crayon: his Hayden Planetarium quietly dropped Pluto from the planet lineup years before the official demotion, and furious kids wrote in. Director of that planetarium since 1996, host of Cosmos: A Spacetime Odyssey and StarTalk, and heir to Carl Sagan in more than spirit: Sagan tried to recruit him for Cornell when Tyson was 17. Also the man who nagged James Cameron until Titanic got its 1912 night sky corrected. Wrote Astrophysics for People in a Hurry.