story musgrave: the moment of truth is coming. you can't run from it anymore, it's coming, there it is. narrator: now, on hubble's 25th anniversary, nova tells the remarkable tale of how this magnificent machine was built, how it has solved some of our most enduring mysteries, and how it is showing us a universe as beautiful as it is astonishing. "invisible universe revealed"-- right now on nova. major funding for nova is provided by the following: we love science. it inspires us to ask interesting questions and find amazing answers. we proudly support nova's efforts to inspire the scientists of today and tomorrow. proper nutrition can help maintain your immune system during cancer treatment. that's why here, dieticians are part of every patient's comprehensive care team. integrative cancer care lives here. learn more at cancercenter.com. the david h. koch fund for science, supportinova and promoting public understanding of science. and the corporation for public broadcasting. and by pbs viewers like you-- thank you. and millicent