"WOW Signal Still Eludes "
Posting by Luke S. Walker
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 April 16, 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 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.
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The now defunct Big Ear Radio Observatory at Ohio State Radio Observatory in Cloumbus , OH. |
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.
What happened to the "Wow!" signal, the most promising transmission from space ever detected by SETI?
SETI (Search for Extra-Terrestrial Intelligence) is the collective name for a number of activities to detect intelligent extraterrestrial life. The organization was founded by Professors Matthew Southwell and Tom Cini who were researchers at the Cavendish Institute. The general approach of SETI projects is to survey the sky to detect the existence of transmissions from a civilization on a distant planet - an approach widely endorsed by the scientific community as hard science.
The United States Government contributed to SETI early on, but recent work has been primarily funded by private sources. There are great challenges in searching across the sky for a first transmission that could be characterized as intelligent, since its direction, spectrum and method of communication are all unknown beforehand. SETI projects necessarily make assumptions to narrow the search, and thus no exhaustive search has so far been conducted.
The circled letter code 6EQUJ5 describes the intensity variation of the signal. A space denotes an intensity between 0 and 0.999.., the numbers 1-9 denote the correspondingly numbered intensities (from 1.000 to 9.999...), and intensities of 10.0 and above are denoted by a letter ('A' corresponds to intensities between 10.0 and 10.999..., 'B' to 11.0 to 11.999..., etc). The value 'U' (an intensity between 30.0 and 30.999...) was the highest ever detected by the telescope. The intensity in this case is the unitless signal-to-noise ratio, where noise was averaged for that band over the previous few minutes.
Ever since it was recorded almost a quarter of a century ago, SETI enthusiasts have speculated about its origin and wondered whether it could be a beacon from an alien civilization.
The latest attempt to relocate the signal, was led by longtime SETI researcher Robert Gray with funding from The Planetary Society. But although Gray and his team used the entire Very Large Array in New Mexico, and although they detected many faint objects in the signal's general vicinity, they found no trace of an alien transmission. As of now, the "Wow" signal remains as enigmatic as ever.
In late 1997, after almost 40 years of operation, the Ohio State University Radio Observatory, with its "Big Ear" radio telescope, ceased operation. The land on which the observatory was sitting (owned by the Ohio Wesleyan University, Delaware, Ohio) was sold by them in 1983 to land developers who later claimed their rights to develop the land. The telescope was destroyed in early 1998. An adjacent 9-hole golf course was expanded into 18 holes and about 400 homes were planned for construction on the nearby land owned by those developers.
Excerpted from The "Wow!" Signal Still Eludes Detection
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