Did we actually receive a message from aliens? On August 15, 1977, while working on a SETI (i.e., Search for Extraterrestrial Intelligence) project at the Big Ear radio telescope of The Ohio State University, Dr. Jerry Ehman detected a strong narrow-band radio signal. The signal lasted for 72 seconds, appeared to be non-terrestrial and originating from outside our solar system.

The Big Ear telescope was fixed and used the rotation of the Earth to scan the sky. At the speed of the Earth’s rotation, and given the width of the Big Ear’s observation window, the Big Ear could observe a given point for just 72 seconds. Therefore, a continuous extraterrestrial signal would be expected to register for exactly 72 seconds. The recorded intensity of that signal would show a gradual peaking for the first 36 seconds, as the signal reached the center of Big Ear’s observation window, and then a gradual decrease. This is exactly what was observed.

Amazed at how closely the signal matched the expected signature of an interstellar communication, Dr. Ehman circled the signal on the computer printout and wrote “Wow!” on its side. This comment became the name of the signal.

Unfortunately, SETI has been unable to confirm the signal, but not for lack of trying. The signal was expected to appear three minutes apart in each of Big Ear’s horns, but that did not happen. Dr. Ehman unsuccessfully looked for recurrences of the signal using Big Ear for months after its detection.

In 1987 and 1989, American data analyst, author, and astronomer, Robert H. Gray, searched for the event using the META array at Oak Ridge Observatory, but did not detect it.

In a July 1995 test of signal detection software, SETI League executive director H. Paul Shuch made several drift-scan observations of the Wow! signal’s coordinates with a 12 meter radio telescope at the National Radio Astronomy Observatory, Green Bank WV. No signal was detected.

In 1995 and 1996, Gray searched for the signal using the Very Large Array, which is significantly more sensitive than Big Ear. Again, no signal was detected.

In 1999, Gray and Simon Ellingsen, an Associate Professor in Physics and Radio astronomy at the University of Tasmania, Australia, searched for recurrences of the event using the 26m radio telescope at the University of Tasmania’s Mount Pleasant Radio Observatory. No signal was detected.

Although, SETI was not able confirm the signal, they were able to determine that the initial signal seemed to have originated from the Sagittarius constellation.

The question “Are we alone in the universe?” is a question humankind has been asking for centuries. The “WOW!” signal appears to suggest we may have company.