The Wow! signal was detected by the Big Ear radio telescope, which was part of Ohio State University's efforts in the Search for Extraterrestrial Intelligence (SETI). On August 15, 1977, the telescope recorded a radio signal from the Sagittarius constellation that was unusually strong and lasted for 72 seconds. The signal's frequency was approximately 1420 MHz, a wavelength associated with hydrogen—one of the most abundant elements in the universe, often considered an ideal frequency for potential extraterrestrial communication. Jerry R. Ehman, a volunteer for the project, was the first to notice the peculiar signal when analyzing the data and famously marked it with the word 'Wow!' on the printout, which has since become synonymous with the occurrence.

The significance of the Wow! signal lies not only in its mysterious nature but also in its implications for the possibility of extraterrestrial life. Despite extensive follow-up attempts to detect the signal again, it has never been reproduced. This mysterious one-time event led to various hypotheses regarding its origin, including natural phenomena, man-made sources, or even signals from extraterrestrial civilizations. The excitement surrounding the Wow! signal reinvigorated public interest and funding in SETI research and inspired numerous scientific discussions and studies in the following years.

The Wow! signal remains one of the most famous signals ever received by SETI researchers. It opened up debates about the potential for intelligent life existing outside our solar system and the methods used to search for extraterrestrial signals. While the specific source of the Wow! signal remains unidentified, its detection highlighted the ongoing quest to understand our place in the universe and the possibility of communication with other intelligent species.