If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?: Seventy-Five Solutions to the Fermi Paradox and the Problem of Extraterrestrial Life

by Stephen Webb

For strong signals, letters were used (with Z being stronger than A). On the night of 15 August 1977, Jerry Ehman spotted the characters “6EQUJ5” on channel 2. This signal started from roughly background level, rose to level U, then decreased back to background level in 37 seconds. This was exactly what an extraterrestrial signal might look like; Ehman circled the characters and wrote “Wow!” in the margin.

Wow