Tonton Streaming Cosmos: A Personal Voyage (1980) S1E12 - Encyclopedia Galactica

Are there alien intelligences? How could we communicate with them? What about UFOs? The answers to these questions take us to Egypt to decode ancient hieroglyphics, to the largest radio telescope on Earth and, in the Spaceship of the Imagination, to visit other civilizations in space. Dr. Sagan answers questions such as: "What is the life span of a planetary civilization?" and "Will we one day hook up with a network of civilizations in the Milky Way galaxy?"