The hosts describe the Universe as they travel it in their Ship of the Imagination. It largely focuses on astronomy and cosmology, but also delves into other sciences, the history of science, and biographies of famous scientists.
It was the most widely watched series in the history of American public television until 1990's The Civil War. It won two Emmys and a Peabody Award, and has since been broadcast in more than sixty countries and seen by over five hundred million people. David Itzkoff of The New York Times described it as "a watershed moment for science-themed television programming".