When the Big Ear Radio Telescope in Delaware, Ohio, was disassembled in 1998 having operated for over 30 years, it was replaced by a golf course. Big Ear was never the world’s biggest radio telescope, nor its most sensitive. But Big Ear nevertheless made one of the most famous observations in the history of astronomy, one that till this day has never been explained.
Throughout the 1970s, Big Ear searched for signals from extraterrestrial civilizations. And on Aug. 15, 1977, it found one — a strong, intermittent signal lasting for 72 seconds, that stood out from the background noise like a searchlight.
