COSMOS_107_08
COSMOS: A SPACETIME ODYSSEY: Host Neil deGrasse Tyson takes us to a time before the Earth was formed to learn how one determined scientist discovered how old our planet truly is in the all-new "The Clean Room" episode of COSMOS: A SPACETIME ODYSSEY airing Sunday, April 20 (9:00-10:00 PM ET/PT) on FOX and Monday, April 21 (9:00-10:00 PM ET/PT) on Nat Geo.