August 15th 1977: Wow! Signal

August 15th 1977: Wow! signal

On this day in 1977, a unusually strong radio signal was detected by the Big Ear Radio Observatory at Ohio State University, as part of the SETI (search for extraterrestrial intelligence) project. The search for radio signals from alien civilisations began in earnest in the 1960s. In August 1977, a radio signal, originating from the direction of the constellation Sagittarius, was detected as thirty times stronger than the average signal. It appeared to be artificial, as it was only heard on one of the observatory’s fifty channels, whereas natural signals cause static on all frequencies. The anomaly thus fit the criteria for an extraterrestrial radio signal, and so shocked SETI scientist Jerry Ehman that he circled it in red ink and wrote ‘Wow!’ next to it, thus giving the signal its name. The Wow! signal only lasted seventy-two seconds, and was never heard again, despite repeated searches. There have been multiple alternatives proposed to explain the signal, but it has never been adequately understood. In 2012, National Geographic and Arecibo Observatory beamed a response comprised of Twitter and video messages from Earth to the location of the Wow! signal, in the hope of contacting alien life.