The Wow! Signal
On 15 August 1977 the Big Ear radio telescope at Ohio State University recorded a strong narrowband radio signal that appeared to come from the direction of the constellation Sagittarius. A few days later, astronomer Jerry Ehman found the reading on the printout, circled it, and wrote Wow! in the margin. The signal has never been detected again and remains unexplained.
Detected
15 August 1977, by the Big Ear telescope near Delaware, Ohio.
Duration
72 seconds, the full window Big Ear could observe that patch of sky.
Direction
The constellation Sagittarius.
Frequency
About 1420 MHz, in the quiet hydrogen line region known as the water hole.
Status
Never repeated, never explained.
"I wrote Wow! because it was the most surprising signal I had ever seen.
"Jerry Ehman
