Encyclopaedia Galactica

Encyclopaedia Galactica is the twelfth episode of Cosmos A Personal Voyage. It first aired 14 December 1980 on PBS.

Summary
Questions are raised about the search for intelligent life beyond the Earth, with UFOs and other close encounters refuted in favor of communications through SETI and radio telescope such as the Arecibo Observatory. The probability of technically advanced civilizations existing elsewhere in the Milky Way is interpreted using the Drake equation and a future hypothetical Encyclopedia Galactica similar to Rosetta Stone is discussed as a repository of information about other worlds in the galaxy.

Cosmos Update
There have been fewer sightings of UFOs and more stories of abductions, while the META scans the skies for signals.