On August 15, 1977 the Ohio State University Observatory detected the signal seen above. It was found at the time that the source was not terrestrial and was moving with the background stars. The coordinates did not match any known solar-type star. This would have been called a valid SETI "contact" except for the fact that the signal did not repeat. This has become known as the "WOW" signal since one of the astronomers made that notation in the margin of the computer printout. (Courtesy: SETI)