Cosmos: A Personal Voyage had 13 episodes.
The original PBS documentary series was created and presented by astronomer Carl Sagan, with Ann Druyan and Steven Soter as co-creators. First broadcast in 1980, it used the history of science, astronomy, evolution, and human civilization to make large scientific ideas accessible to a general audience.
Its 13 episodes ranged widely. Early installments introduced the “Ship of the Imagination,” the cosmic calendar, evolution, and the development of astronomy. Later episodes examined the lives of stars, the search for extraterrestrial intelligence, nuclear danger, and humanity’s long-term future. The final episode, “Who Speaks for Earth?”, asked how humanity might represent itself to other civilizations.
Some releases can cause confusion because a later home-video edition included a special interview episode featuring Sagan and Ted Turner. That extra program is not part of the original 13-episode series. The companion book Cosmos also follows the series with 13 corresponding chapters.