Friday, July 18, 2008

Is anyone looking for extraterrestrial life?

Despite the fact that alien life forms have never been discovered, the search for extraterrestrial intelligence (or SETI, as it is called) remains a popular pursuit. Astronomers (scientists specializing in the study of matter in outer space) believe that if life does exist on other planets, we now possess the technological capability of finding it and perhaps even communicating with it.
Most modern SETI missions use radio telescopes—instruments consisting of a large concave dish with an antenna at the center, tuned to a certain wavelength, that receive and process radio waves. The radio telescopes, tuned to nearby stars, listen for signals that may have been sent by alien civilizations.
The first large-scale SETI experiment, called Project Ozma, was begun by astronomer Frank Drake (1930-) in 1960. Drake conducted Project Ozma at the National Radio
Astronomy Observatory at Green Bank, West Virginia. The object of the experiment was to search for signs of life in distant solar systems through intergalactic radio waves.

Unidentified flying object (UFO) expert J. Allen Hynek (1910-1986) developed the following scale to describe encounters with extraterrestrial beings or vessels:
Close Encounter of the First Kind— sighting of a UFO at close range with no other physical evidence.
Close Encounter of the Second Kind—sighting of a UFO at close range, but with some kind of proof, such as a photograph, or an artifact from a UFO.
Close Encounter of the Third Kind— sighting of an actual extraterrestrial being.
Close Encounter of the Fourth Kind— abduction by an extraterrestrial spacecraft.