one of the many great NOVA documentaries  on PBS.org

NOVA examines how a simple instrument, the telescope, has fundamentally changed our understanding of our place in the universe. This tale of human ingenuity involves some of the most colorful figures of the scientific world Galileo, Kepler, Newton, William Herschel, George Hale and Edwin Hubble leading up to todays colossal telescopes.

Now, at the center of an international space race, a new generation of ever-larger telescopes is poised to reveal answers to longstanding questions about our universe and, in turn, to raise new questions.