Wow! Signal - Time Variation

Time Variation

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. A continuous 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"— and then a gradual decrease.

Therefore, both the length of the Wow! signal, 72 seconds, and the shape of the intensity graph may correspond to a possible extraterrestrial origin.