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 heard again

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 heard again

The most famous document in the search for alien life is a strip of computer printout with six characters circled in red biro. Those characters are 6EQUJ5. A volunteer astronomer named Jerry Ehman found them a few days after 15 August 1977, working through a pile of paper from the Ohio State University Radio Observatory, an instrument so vast and so ungainly that everybody called it the Big Ear. He ringed the sequence and scrawled one word besid…