Life Beyond Earth

Strange Radio Signal From Space Still a Mystery 40 Years Later: Alien Communication?

Wow! Signal
A printout of a radio signal from space detected on Aug. 15, 1977. It became known as the "Wow!" signal after astronomer Jerry Ehman wrote that exclamation next to it, expressing his shock at the unusual find. (Ohio State University Radio Observatory and the North American AstroPhysical Observatory)

On Aug. 15, 1977, a 72-second radio signal from space stirred up the Search for Extra-Terrestrial Intelligence (SETI). Astronomer Jerry Ehman viewed the signal on...