SETI (World of Earth Science)
SETI (The Search for Extraterrestrial Intelligence) is a term that encompasses several different groups and their efforts to seek out intelligent extraterrestrial life. The driving force behind these groups is the ancient human desire to understand the origin and distribution of life throughout the Universe. As technology progresses, SETI efforts move from the study of extraterrestrial rocks and meteors towards scanning the skies for a variety of signal types.
Cornell University professor Frank Drake founded the first SETI program in late 1959. Drake reinforced his idea of scanning the skies with his famous Drake Equation. The Drake Equation predicts the abundance of intelligent life within a certain galaxy.
The second major development of SETI took shape in the late 1960s when NASA joined the program. NASA was minimally involved the project, but spawned many SETI related programs. These programs included the Microwave
Observing Project, Project Orion, the High Resolution Microwave Survey, Toward Other Planetary Systems, and more. One of the most intensive SETI related programs NASA would initiate began in 1992, but Congress cut funding for the program within a year. SETI projects now must rely on private funding, and SETI operates through the SETI Institute, a non-profit corporation.
Historically, scientists used several different methods for searching for extraterrestrial intelligence. The earliest method, and still most commonly used in present research, is the scanning of electromagnetic emissions. Radio waves are picked up by an array of radio telescopes and scanned for non-random patterns. More modern methods expand the search to other regions of the electromagnetic spectrum, including the infrared spectrum.
As of 2002, the University of California at Berkeley hosts the most widespread SETI effort in history. Berkeley projects include SETI@Home, SERENDIP, Optical SETI, and Southern SERENDIP. SETI@Home collects its data in the background of the Arecibo Radio Observatory and relays it back to the lab in Berkeley. The data is then divided into workunits and sent out to the personal computers of volunteers throughout the world. These personal computers scan the data for candidate signals. If a candidate signal appears, it is relayed back to Berkeley, where the signal is checked for data integrity. Finally, the lab removes radio interference and scans the data for final candidates. The Berkeley faction of SETI will be expanding their efforts with the Allen Telescope Array (formerly known as the One Hectare Telescope) designated specifically for this research.
Project Phoenix, also run by the SETI Institute, concentrates on obtaining signals from targeted areas within our galaxy. The focused Phoenix receiver can amass radio energy for longer periods of time and with greater sensitivity than previous SETI radio telescopes, allowing for faster and more precise analysis.
Although only a small fraction of the sky has been scanned, so far, SETI initiatives have not confirmed a signal from an extraterrestrial source that is conclusive proof of an extraterrestrial intelligence. A few strong and unexplained signals have intrigued SETI scientists; the most well known was received in 1977 at the Ohio State Radio Observatory. None of the signals have ever repeated.