"Invisible Universe Revealed" on PBS/NOVA
Twenty-five years ago, NASA launched one of the most ambitious experiments in the history of astronomy: the Hubble Space Telescope. In honor of Hubble's landmark anniversary, NOVA tells the remarkable story of the telescope that forever changed our understanding of the cosmos. Airs at 9 p.m. April 22 on PBS. (Check local listings for airtime.) Streaming will be available after the airdate.