For more than 40 years, astronomers have used microwave radio telescopes to try to detect signals from extraterrestrial aliens. Both Guglielmo Marconi and Nikola Tesla at one time claimed they had detected radio signals from aliens, but it was not until 1959 that a thorough search began. In that year, Cornell University astronomers Phillip Morrison and Giuseppi Cocconi proposed using large radio telescopes to try to receive these messages, if they in fact exist. They claimed that any intelligent civilization would probably broadcast at a frequency of 1420MHz, wavelength of 21 centimeters, because this is the emission resonance frequency of hydrogen, the most common atom in the universe.
An accidental finding was the discovery of pulsars, thought originally to be generated by ET signals. The actual pulsar discovery apparently was not linked to a SETI search... [[needs more info..]
The search continues today as a smaller, privately funded project, and over the years public awareness of SETI has grown. Its profile was raised considerably following the release of Carl Sagan's book 'Contact' and its subsequent film adaptation, which featured fictionalized SETI scientists at work at the Arecibo, Puerto Rico radio telescope facility and the Very Large Array radio telescope complex in New Mexico, both of which have actually been used for SETI research in the past.
The SETI Institute was established in the early 1960's as a coordinated group to promote SETI observations.
A strong 'amateur SETI' movment exists, mainly among amater radio operators who have equipment that operates around the 130MHz to 1420Mhz part of the radio spectrum.
SETI in Films
- Carl Sagan's book 'Contact' and its subsequent film adaptation;
- Close encounters of the 3rd kind;