Wow! signal
The Wow! signal was a strong narrowband radio signal detected on August 15, 1977, by Ohio State University's Big Ear radio telescope in the United States, then used to support the search for extraterrestrial intelligence. The signal appeared to come from the direction of the constellation Sagittarius and bore expected hallmarks of extraterrestrial origin.
Astronomer Jerry R. Ehman discovered the anomaly a few days later while reviewing the recorded data. On the computer printout, he circled the reading of the signal's intensity, "6EQUJ5", and wrote the comment "Wow!" beside it, leading to the event's widely used name.[2]
The entire signal sequence lasted for the full 72-second window during which Big Ear was able to observe it. Despite numerous follow-up searches and hypotheses (including brief consideration of reflections from space debris, interstellar scintillation, and comet hydrogen clouds), the signal has never recurred, and no explanation, terrestrial or otherwise, has been confirmed. While some researchers have suggested it could represent an extraterrestrial transmission, its single occurrence and lack of replication limit the strength of this interpretation. The Wow! signal has inspired targeted searches, scientific discussion about rare astrophysical phenomena, and references in popular culture.
