For 72 seconds in August 1977, an Ohio radio telescope picked up a signal thirty times stronger than the background hum of space, sitting almost exactly on the frequency scientists had guessed an alien civilization would choose — and it has never been hear

• A radio telescope in Ohio detected a signal in August 1977 that was thirty times stronger than background noise, occurring almost exactly on the frequency scientists had predicted for an alien civilization.

AI-generated summary of the original article — see the source for the full story.