Looking for ET

In what could be a technical tour de force for radio astronomy, the University of California at Berkeley and the SETI Institute are laying plans for an array of up to 1,000 interconnected radiotelescopes to search for signals from extraterrestrial civilizations.

The system's architects say that the array's unique design will also allow the study of less exotic quary from natural radio sources in the solar system to objects at the edge of the known universe. Funding for the $25 million facility, which is to use off-the-shelf equipment, will come from private donations through the nonprofit SETI Institute.

"We're really excited about this," says Jill Tarter, lead scientist at the institute. Such an array would mark the first time SETI researchers have virtually full-time access to a world-class radiotelescope.

The effort comes at time when the search for intelligent life elsewhere is gaining academic respectability. This week, UC Berkeley announced the appointment of Dr. Tarter's husband, astronomer William Welch, to a newly endowed chair dedicated to the search for extraterrestrial intelligence.

Planners for the new radiotelescope array are entering the realm of choreography as much as radio astronomy. They envision 500 to 1,000 large satellite-TV antennas linked to track regions in the sky as one telescope. The signals from each dish will be combined electronically to yield the resolving power of a single dish with an area of 10,000 square meters - larger than the radiotelescope at Aricebo, Puerto Rico, currently the world's largest.

Within each dish's field of view, however, each of up to 100 "beams" can be electronically directed at individual radio targets, in principle allowing scientists to gather data on 100 different targets simultaneously, says Leo Blitz, director of Berkeley's Radio Astronomy Laboratory.

"Our goal," he says, "is nothing short of standing the way radio astronomy has been done up to now on its head."