A mysterious strong narrowband signal was received on August 15, 1977, by Big Ear Radio telescope in the United States, Ohio State University. The signal was recognized to have come from the constellation Sagittarius and had the hallmarks of coming from an extraterrestrial origin.
Astronomer Jerry R. Ehman discovered the anomaly a few days later when he was reviewing the recorded data. The signal lasted for 72 seconds. He was excited by the result, circled the readings on the printout and wrote Wow! on its side. This is how the signal from constellation Sagittarius got its name of Wow!
The Wow! signal is the strongest alien radio transmission ever detected and it signifies that aliens do exist.