What was the mysterious Wow! signal?
One striking radio observation remains interesting precisely because it has not repeated conclusively.
A brief surprise in 1977
The Big Ear radio telescope in Ohio detected a strong narrowband radio signal during a search of the sky in August 1977. Astronomer Jerry Ehman later noticed the unusual measurement on a computer printout and wrote “Wow!” beside it. The nickname stuck, and the event became one of the best-known stories in the search for extraterrestrial intelligence.
Why it attracted attention
The strength and frequency pattern were intriguing, and the telescope was observing a region of the sky near Sagittarius. But the signal was brief and has not been reliably detected again despite follow-up efforts. Without repetition or additional independent observations, scientists cannot determine its source with confidence.
Mystery is not proof
Natural astrophysical phenomena, interference and other possible explanations have been discussed. The available evidence does not establish that the signal came from aliens, nor does it conclusively settle on one alternative. Its scientific value lies partly in showing why repeatability and careful elimination of mundane causes are essential when interpreting unusual measurements.
External references are provided for exploration; Curio Hour’s explanation is written separately.