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Academics => Science and Astronomy => Topic started by: Denzx on February 14, 2014, 11:59:31 AM
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The Wow! signal was a strong narrowband radio signal detected by Jerry R. Ehman on August 15, 1977, while he was working on a SETI project at the Big Ear radio telescope of The Ohio State University, then located at Ohio Wesleyan University's Perkins Observatory in Delaware, Ohio.[1] The signal bore the expected hallmarks of non-terrestrial and non-Solar System origin. It lasted for the full 72-second window that Big Ear was able to observe it, but has not been detected again. The signal has been the subject of significant media attention.
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.
Interstellar scintillation of a weaker continuous signal—similar in effect to atmospheric twinkling—could be an explanation, but that would not exclude the possibility of the signal being artificial in origin. But even the significantly more sensitive Very Large Array could not detect the signal, and the probability that a signal below the Very Large Array level could be detected by the Big Ear 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.[4]
Ehman has voiced doubts that the signal was of intelligent extraterrestrial origin: "We should have seen it again when we looked for it 50 times. Something suggests it was an Earth-sourced signal that simply got reflected off a piece of space debris."[9] He later recanted his skepticism somewhat, after further research showed an Earth-borne signal to be very unlikely, given the requirements of a space-borne reflector being bound to certain unrealistic requirements to sufficiently explain the signal.[10] Also, the 1420 MHz signal is problematic in itself in that it is "protected spectrum": bandwidth reserved for astronomical purposes in which terrestrial transmitters are forbidden to transmit.[11][12] In his most recent writings, Ehman resists "drawing vast conclusions from half-vast data"—acknowledging the possibility that the source may have been military or otherwise a product of Earth-bound humans.
Wiki link:
http://en.wikipedia.org/wiki/Wow (http://en.wikipedia.org/wiki/Wow)!_signal
Other links:
http://news.discovery.com/space/alien-life-exoplanets/the-wow-signal-130524.htm (http://news.discovery.com/space/alien-life-exoplanets/the-wow-signal-130524.htm)
Scientists say that if the signal came from extraterrestrials, they are likely to be an extremely advanced civilization, as the signal would have required a 2.2-gigawatt transmitter, vastly more powerful than any on Earth.