Carl Sagan and the Search for Extraterrestrial Intelligence (SETI)

Carl Sagan was one of the most visible and credible advocates for the Search for Extraterrestrial Intelligence (SETI), a scientific effort to detect signs of intelligent life beyond Earth. At a time when the idea of contacting alien civilizations was often dismissed as science fiction, Sagan argued for its legitimacy as a branch of astronomy and planetary science. He emphasized that the search was not about UFO mythology or sensational claims, but about using powerful radio telescopes to scan the skies for structured, non-random signals—potentially evidence of advanced technology elsewhere in the cosmos. Sagan collaborated with other researchers to develop methods for identifying such signals and explored the probabilities of life arising in the universe using the Drake Equation as a guiding framework. While acknowledging that the likelihood of immediate contact was slim, he maintained that the act of searching was itself a profound scientific and philosophical statement: that humanity was ready, at least in principle, to join a larger cosmic conversation.