The search for extraterrestrial intelligence (SETI)--to the layman it sounds like a bit of futuristic fancy. But many scientists say it's an idea whose time has come--and whose time will soon be gone.
''Are we alone? is a very, very important question,'' says Dr. Bruce Murray, director of the Jet Propulsion Laboratory. ''We are at the point in the development of technology where it is possible for us to detect radio signals from throughout the galaxy that are intended to be detected.''
But at the same time, Earth's atmosphere is growing so clogged with man-made radio noise--from satellites to television signals--that within 10 to 20 years it may be nearly impossible for an earthbound receiver to detect radio signals from some other intelligent source in the galaxy.
It is this ''window of time'' that lends a sense of urgency to a recent request by the National Aeronautics and Space Administration (NASA), made at a Capitol Hill hearing, for a congressional go-ahead on a five-year SETI project.
The project, which would cost $2 million to $2.5 million a year--out of a $6. 5 billion NASA budget--involves the development and testing of a highly sophisticated, computerized radio receiver that could simultaneously scan millions of channels of radio frequencies across the universe. Such a receiver would be a million times more effective than conventional radio receivers.
Because of the vast distances involved--measured by light years--scientists say that radio is the easiest, and most likely, way a civilization would make itself known.
Not all scientists believe that intelligent life exist in the universe, but many scientists say that there is reason to believe that some form of intelligence may exist somewhere in the universe.
''It's not a flaky thing, it deserves scientific investigation,'' says Dr. Thomas R. McDonough, SETI coordinator for the Planetary Society, a public membership group dedicated to supporting and understanding planetary exploration and the search for evidence of intelligent life elsewhere in the universe.
''The current scientific attitude,'' he continues, ''is that there are so many reasons to think intelligent life exists out there, why not perform easy, cheap experiments with radio signals?''
Popular interest in life on other planets dates back at least to the mid-19th century when Americans were swept up by the idea that there might be life on Mars. That interest was sparked by astronomer Percival Lowell, who misinterpreted the findings of an Italian astronomer who said he had seen ''channels'' on Mars. Lowell translated the Italian's findings as ''canals,'' a word more fraught with implications of human life.
Modern interest in SETI was sparked more than two decades ago by a paper by scientists Philip Morrison and Giuseppi Cocconi
Serious scientific investigation began in 1960 when scientists Frank Drake and Carl Sagan, and a handful of other researchers, began to make the search for extraterrestrial intelligence a respectable scientific undertaking.
Nonetheless, SETI projects have had a rough time under NASA. Although the USSR has shown strong interest in SETI research, American SETI projects have been slow to get off the ground--hampered at first by divisiveness within the astronomical community, and later from political fallout.
Twice before NASA has tried to get congressional funding for the SETI project now proposed. The first time, Sen. William Proxmire (D) of Wisconsin singled it out for one of his ''Golden Fleece'' awards, as an example of waste of the government's money. Last year, Senator Proxmire again axed the project by entering a budget amendment that expressly forbade NASA from spending one penny of its money on SETI research.
This year, scientists like Dr. Sagan have gone out of their way to meet with Senator Proxmire to explain the SETI proposal. Although a Proxmire aide says the senator has not yet made up his mind, there appears to be cautious optimism that the project will go through.
If not, the Planetary Society--founded in 1980 by Dr. Sagan and Dr. Murray-- is preparing to mobilize its forces to rescue the SETI project. Already, it has donated several thousand dollars, given by society members, to two university-connected SETI projects.
Although the society has nowhere near the financial resources needed to fund NASA's SETI project, says Dr. McDonough, it has some $40,000 it can contribute to garnering public support and private dollars for the project.