In 1977, a powerful narrow-band radio signal was detected from the direction of the Sagittarius constellation. Known as the “Wow! Signal,” it remains one of the strongest candidates for extraterrestrial communication.
Key Points
Detected by the Big Ear Radio Telescope on August 15, 1977.
The 72-second signal matched characteristics expected from a non-human intelligent source.
No satellite, comet, or natural cosmic event fully explains the frequency pattern.
Repeated searches for the same signal have failed—it never appeared again.
Considered one of SETI’s greatest unsolved mysteries.