NASA's Search for Extraterrestrial Intelligence (SETI) program is no more. Long live the High Resolution Microwave Survey. But whatever you call it, the United States National Aeronautics and Space Administration is about to fire up the most powerful search for signs of alien civilizations yet mounted.
The $100 million program aims to survey the entire sky by the year 2010 and specifically target about a thousand stars.
The searches "turn on Oct. 12 [Columbus Day], and we can't wait," project scientist Jill Tarter of the University of California at Berkeley exclaimed, describing the program to the press during the World Space Congress here.
Dr. Tarter and her project colleagues have been preparing for this day for more than a decade. However, they find that calling their effort SETI doesn't play well in the US Congress.
Budget-cutting critics sneer at it as "irrational." This is in spite of the fact that the US National Academy of Science and the International Astronomical Union have endorsed SETI as valuable astronomical research. NASA's SETI budget has survived these attacks in the past. But with the program about to move from development work to its operational phase, this annual uncertainty became intolerable. John D. Rummel, SETI program scientist at NASA headquarters, explained that project members would hate to s ee anything come between them and the fruition of all the activities that have been paid for so far. So they are recasting the program in terms of what he calls "a broader context."
Looking for alien signals will be only part of an effort that also will search for nearby planetary systems and for conditions that favor the rise of organic life. Tarter noted that this could change the list of stars for the targeted search. The project had listed sun-like stars on the presumption that they might be most likely to have life-supporting planets. Now the list may include lower-mass stars that might have only giant Jupiter-like planets.
Tarter further explained that project members are talking with conventional radio astronomers to see how the new equipment might be used for non-SETI research. The heart of this new technology is a powerful data-analyzing capability, not any new kind of radio-telescope antenna. The project will use existing telescopes, both in the United States and in several other nations. The new technology allows a telescope to "listen" on tens of millions of narrowly defined microwave channels simultaneously and to p rocess the data immediately to look for possible signals. A new way of looking
Radio astronomers have never had this kind of capability before. Noting this, Ronald D. Ekers, director of the Australian Telescope National Facility at Epping, New South Wales, commented: "When you observe the universe in a way that's never been done before, you discover a lot of new things."
Although SETI may have a high giggle rating in the US Congress, attendees at the space congress take it very seriously. They packed a symposium to standing room only as scientists from Argentina, Australia, France, India, Japan, Russia, and the US reported SETI research and planning in their countries. Fernando R. Colomb of the Institute for Radio Astronomy at Buenos Aires noted that the "symposium brought together people from several different cultures and traditions with a common purpose. He quickly ad ded, "No signal has been detected to date."
In saying this, he reflected a general concern among SETI scientists about raising public expectations too high. They continually stress that the search may take a long time before finding a signal, if ever. Tarter pointed out that, powerful as it is, the new NASA project has a very limited reach. It is designed to detect leakage radiation of a strength similar to Earth's general radio chatter - and only from the nearest stars. It could, however, detect the equivalent of a beam of our most powerful radar s from stars half way to our galaxy's center. SETI pioneer Bernard M. Oliver, deputy director of the NASA project at the NASA Ames Research Center in Mountain View, Calif., illustrated this limited reach using a photo of the Andromeda Galaxy. Just a beginning
The galaxy is similar to our Milky Way. He drew a small circle with a tiny dot inside, well to one side of the galaxy center. The dot represented the expected range of the new NASA SETI search.
"How many of you would conclude from our failure to find a signal that there were no [intelligent beings] in the entire galaxy?," he asked. He added: "We have left our house but are hardly down the front steps. What do we know about life elsewhere?"