The Wow Signal (Stephen Wright)

The Wow! Signal was a strong, unusual radio signal detected by astronomer Jerry Ehman in 1977 using the Big Ear radio telescope. Lasting about 72 seconds, it appeared to originate from a specific point in space associated with the constellation Sagittarius. Its characteristics—intensity and frequency—matched what scientists might expect from a sign of extraterrestrial intelligence, though no repeat has been observed. The signal remains one of the most intriguing and unexplained anomalies in SETI research, sparking ongoing curiosity about whether it was a natural phenomenon, human-made interference, or evidence of extraterrestrial communication.