The Shores of the Cosmic Ocean is the first episode of Cosmos A Personal Voyage. It first aired 28 September 1980 on PBS.
Carl Sagan describes the cosmos and a Ship of the Imagination shaped like a dandelion seed. He takes the ship on journeys through the universe's hundred billion galaxies, the Local Group, the Andromeda Galaxy, the Milky Way, the Orion Nebula, our Solar System, and finally, planet Earth. Eratosthenes' successful calculation of the circumference of Earth leads to a description of the ancient Library of Alexandria. Finally, the "Ages of Science" are described, before pulling back to the full span of the Cosmic Calendar.
- The revised version of this episode adds an introduction by Ann Druyan, recorded after Sagan's death, in which she discusses some of the changes that occurred in the years after its broadcast.