Thursday, February 14, 2008


The Wow! signal was a strong, narrowband radio signal detected by Dr. Jerry R. Ehman on August 15, 1977 while working on a SETI (Search for Extraterrestrial Intelligence) project at the Big Ear radio telescope of the Ohio State University. The signal bore expected hallmarks of potential non-terrestrial and non-solar system origin. It lasted for 72 seconds, the full duration Big Ear observed it, but has not been detected again. It has been the focus of attention in the mainstream media when talking about SETI results. 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 any given point for just 72 seconds. An extraterrestrial signal, therefore, would be expected to register for exactly 72 seconds, and the recorded intensity of that signal would show a gradual peaking for the first 36 seconds — until the signal reached the center of Big Ear’s observation “window” — at which time it would show a gradual decrease. Therefore, both the length of the Wow! signal, 72 seconds, and its shape would correspond to an extraterrestrial origin. The region of the sky in which the signal was heard, lies in the constellation Sagittarius, roughly 2.5 degrees south of the fifth-magnitude star Chi-1 Sagittarii.

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