Today in 1977, we received a radio signal from deep spaceThe "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 Ohio State University. The signal bore expected hallmarks of potential non-terrestrial and non-solar system origin. It lasted for the full 72 second duration that Big Ear observed it, but has not been detected again. Much attention has been focused on it in the media when talking about SETI results.
Amazed at how closely the signal matched the expected signature of an interstellar signal in the antenna used, Ehman circled the signal on the computer printout and wrote the comment "Wow!" on its side. This comment became the name of the signal.
Determining a
precise location in the sky was complicated by the fact that the Big Ear telescope used two feed horns to search for signals, each pointing to a slightly different direction in the sky following Earth's rotation; the Wow! signal was detected in one of the horns but not in the other, although the data were processed in such a way that it is impossible to determine in which of the two horns the signal entered…The
declination was unambiguously determined...This region of the sky lies in the constellation
Sagittarius, roughly 2.5 degrees south of the fifth-magnitude star group
Chi Sagittarii.
Interstellar scintillation of a weaker continuous signal -- similar, in effect, to atmospheric twinkling -- could be a possible explanation, although this still would not exclude the possibility of the signal being artificial in its nature. However, even by using the significantly more sensitive Very Large Array, such a signal could not be detected, and the probability that a signal below the Very Large Array level could be detected by the Big Ear radio telescope due to interstellar scintillation is low.[6] Other speculations include a rotating lighthouse-like source, a signal sweeping in frequency, or a one time burst. Some have also suggested it could have come from a moving space vehicle of extraterrestrial origin.
-- reprinted from
Wikipedia[Editor's Note: For the month of August, the 13.7 Billion Years "We'll Drink to That" Series presents a fine reason to raise a glass and make a toast. Viva!]
image: A scan of a color copy of the original computer printout, taken several years after the 1977 arrival of the Wow! signal (credit: The Ohio State University Radio Observatory and the North American AstroPhysical Observatory (NAAPO))