The Wow Signal

 
The algorithms of the SETI@home client search for signals which have the following structure: A signal (Gaussian, triplet or pulse) arises only in a single narrowband channel. All other channels contain noise. Up to now we do not know cosmic phenomena which would generate such signals. It would seem improbable that they have no artificial origin. The picture shows a computer generated example of a strong Gaussian signal.

A cosmic radio signal which has the above structure was really observed. An internet publication of the Planetary Society describes its discovery:

"It was recorded at the Big Ear radio telescope at Ohio State University on the night of August 15, 1977. Jerry Ehman, a volunteer and a professor at a local university who was checking the computer logs the following morning was so startled by what he saw that he jotted "Wow!" next to the signal printout. The signal, the most promising radio transmission ever detected by SETI, became enshrined as the "Wow!" signal." (Planetary Society 2001)

The SETI@home project of the University of California, Berkeley, started much later in 1999. The following picture shows a graphic which was produced by the SETI@home screen saver from the data of the Wow signal.

References

• Amir Alexander and Eric Heien, Know What to Expect When ET Calls. Planetary Society, 2001.
• The graphics were generated by means of two animations S@h_movie17.avi and S@h_movie17.avi which can be downloaded from the above publication of the Planetary Society. (Use "Shift" + "Left Mouse Button".)
• Amir Alexander, The Search for Extraterrestrial Intelligence: A Short History. Planetary Society, 2001.