'Cosmos: A Spacetime Odyssey' Visits Halley's Comet | Preview Clip

Host Neil DeGrasse Tyson and the 'Ship of the Imagination' travel to the comet at edge of the solar system and explains how it 'falls' back to the inner solar system. The all-new "When Knowledge Conquered Fear" episode airs March 23 on Fox.
credit : Courtesy of Fox Broadcasting