A 2006 handout photo made available by the BBC from an episode of "Doctor Who" showing Billie Piper, left, as Rose Tyler and David Tennant as The Tenth Doctor. "Doctor Who" is turning 50 and the BBC is throwing a broadcasting blowout for the sci-fi show, which began with little fanfare and few expectations on Nov. 23, 1963 but is now one of its biggest hits and major exports. (AP Photo/BBC, Mike Hogan)