SETI

The SETI Institute, founded in 1984, is a private non-profit center for research and education related to the scientific search for extraterrestrial life. SETI is the acronym for Search for Extraterrestrial Intelligence, the umbrella term for all endeavors, especially those using radio telescopes, to find signs of intelligent life elsewhere in the Universe. SETI assumes that life exists on some Extra-solar planets; a small percentage of that life is sufficiently advanced to have developed civilizations and technological capabilities; such civilizations are either unintentionally emitting or deliberately transmitting signals that are detectable across intervening space; and such signals if received will be identifiably of artificial origin.

A vast number of stars must first be checked for the presence of suitable planetary systems, very few of which will contain planets potentially suitable for complex life, and very few of those may be expected to host technologically advanced civilizations. Natural cosmic radio sources produce ‘noise’ spread across a wide frequency range. Radio SETI experiments look for narrowband signals, with a frequency spread of just a few hertz, characteristic of a purpose-built transmitter – these are the easiest signals to detect as their energy is concentrated in a small region of the radio spectrum.

The earliest serious attempt to detect ETI signals was Project Ozma (the name is from Frank Baum’s The Wizard of Oz). In 1960 Frank Drake and others used a 26-m (85-ft) antenna at Green Bank to search at the 21-cm hydrogen line. Ozma was unsuccessful and was abandoned after a few months. Since then a number of other projects, mostly privately funded, have scanned the heavens in various regions of the radio spectrum.

The SETI Institute currently encompasses more than 30 research projects. The most visible of these is Project Phoenix, the world’s most sensitive search for extraterrestrial intelligence. Begun in 1995 at the Parkes 210 ft radio telescope in Australia, Phoenix moved to the 140 ft telescope at the National Radio Astronomy Observatory in Green Bank, West Virginia in 1996. From fall of 1998 through the summer of 2003, observations will take place at the 1000 ft Arecibo radio telescope in Puerto Rico. Project Phoenix is a targeted search which scans billions of frequency channels for narrow-band continuous wave and pulsed signals from nearby Sun-like stars. It commands slightly more than half of the Institute’s total operation, and is privately funded. The Institute is now developing and prototyping new system designs for next generation SETI.

The balance of research projects at the SETI Institute fall within the Institute’s Center for the Study of Life in the Universe. These projects investigate the origin and evolution of life on Earth and possibilities for life elsewhere. Most of this work is currently funded through competitively won peer-reviewed government research grants.

Questions to Ponder

• Is there oxygen in the atmospheres of other planets?
• What is a Dyson Sphere?
• Which part of the sky did the famous 'wow' signal originate from?
• Why does the SETI project search for radio signals?