On August 15, 1977, the Big Ear radio telescope in Ohio detected an extraordinarily strong narrowband radio signal during a search for extraterrestrial intelligence. When astronomer Jerry Ehman later examined the computer printout, the signal was so striking that he circled the data and wrote a single word beside it. Wow. ([SETI Institute][1])

This episode examines what the telescope actually detected, why the signal attracted scientific attention, and why repeated searches failed to find it again. Modern researchers have proposed natural astrophysical explanations, but none has yet established the source with certainty. ([SETI Institute][2])

Was the Wow Signal an unusual natural event, unidentified interference, or something astronomers happened to hear only once?