The show's format is based on previous BBC documentaries such as Kenneth Clark's Civilisation, Jacob Bronowski's The Ascent of Man and David Attenborough's Life on Earth. (The BBC repaid the compliment by screening the series, but episodes were cut to fit 50-minute slots and shown late at night.) However, unlike those series, which were shot entirely on film, Cosmos used videotape for interior scenes and special effects with film being used for exteriors.
The series is notable for its groundbreaking use of special effects which allowed Sagan to apparently walk through environments that were actually models rather than full-sized sets.
Sagan's historical description of Hypatia of Alexandria and the burning of the Library of Alexandria has been criticized by historians who interpret the sources on Hypatia's life and the end of the library differently and who believe that Sagan should have made clear that there is a scholarly controversy on this issue. Other parts of Cosmos were controversial among the general public, though hardly among scientists, such as Sagan's straight-forward treatment of astrology as a pseudoscience and his equally straight-forward description of biological evolution.
Cosmos has long been unavailable after its initial release because of copyright issues with the included music, but has recently been re-released on Region 1 DVD. As of September 2003 there has been no news of a Region 2 release.
The thirteen parts are:
I: The Shores Of the Cosmic Ocean
XIII: Who Speaks For Earth?
Carl Sagan also wrote a book called Cosmos (1980), which is similarly structured and contains most of the information from the series, and some information not found in it. This book is still in print as of 2002.