The SETI Pioneers

After WWII, it became apparent to a few pioneers, amonng them the astronomer Charles Drake, that advances in communiation techology developed during the War could be put to use to answer the question: are there civilizations outside the Earth? In a landmark paper published in the British scientific journal "Nature", Giuseppe Cocconi and Philip Morrison argued on the probable existance of other civilizations and on the detection of radio waves as a wy to find out whether there are other inhabited planets orbiting other stars. Drakes' first effort (in 1960) was dubbed "Ozma" (from the "Wizard of Oz") and required to listen to (or "sample") channels (i.e., narrow intervals of frequency) around the 21cm line. (The 21cm line is an important one in astrophysics. H atoms emit at that wavelength and it is ubiquotus in space).
Other scientists began interested in exploring the possibility of life outside the Earth; most notably, Carl Sagan, from Cornell University, although best known to laypersons as a gifted popularizer of astronomy and space science, worked on many aspects of research related to the search for life on other planets. The 70s saw the launch of several programs. Then as now, it was hard to obtain funds and time at radiotelescope for this type of searches. Several strategies were used to persue searches; in one, named SERENDIP (Search for Extraterrestrail Emission from Nearby Developed Intelligent Populations), was cuncurrent to other research work and used signals that were "discarded" by other researchers. In another strategy, instruments and telescopes were built and dedicated to extraterrestrial searches, such as the program at Ohio State University and at Harvard University.

In the 80s, work began at NASA Ames sand JPL (Jet Propulsion Laboratory) on the construction of dedicated instruments for systematic searches. The High Resolution Microwave Survey was an ambitious project within the NASA sponsored program named SETI to search 1,000 stars within 100 light-years. The Arecibo Telescope (1,000 foot in diameter dish) was one of the radiotelescoped to be used. Each star would be "looked at" for a few minutes, and signals would be sampled with frequency in the 1-3 GHz (10⁹ Hertz -oscillations per second, or 10 to 30 cm wavekength) region.
As the survey was well underway, in October 1993 Congress decided to cut ALL funds to the SETI project. To find out what happened next, go to the Section "Current Searches".