Anybody out there? A new generation of listening posts might hear their call

Two Harvard astronomers have proposed a new way to search for alien civilizations.

In the past, scientists involved in the search for extraterrestrial intelligence -- or SETI -- have monitored radio waves at frequencies much higher than those used for FM radio, television, and most other applications.

The advantage of this is that it is much easier to detect signals at those frequencies without all the interference from earthbound sources. The trouble is that aliens might use the same lower frequencies we use and we'd miss their broadcasts. (Some people have speculated, though, that the aliens might construct a high-frequency beacon to deliberately attract attention -- a kind of interstellar "We are here; anyone out there?")

Now, say Avi Loeb and Matias Zaldarriaga of the Harvard-Smithsonian Center for Astrophysics, a new generation of radio telescopes under construction in remote locations will be able to monitor these lower frequencies. The telescopes are being built for other purposes -- to explore the cosmology of the early universe -- but the data could be scrubbed for signs of alien chatter.

Loeb said that he is involved with one of these telescopes, the Mileura Wide-Field Array in western Australia, and that he plans to get a student to develop SETI software to monitor its observations. It is scheduled to begin operation next year.

This raises the possibility that the first communication would not be a somber "we come in peace" but a fragment from the alien equivalent of "I Love Lucy" reruns.

GARETH COOK