SETI@home Expands
The SETI@home project released a major upgrade in October in its
quest to scan the sky for signs of intelligent life in the universe.
Nearly 2.5 million people have downloaded previous versions of
the SETI@home software, which analyzes radio-telescope data for
artificial signals from among the stars. The new version 3.0 of
the software (available at http://setiathome.berkeley.edu/) performs
a deeper analysis of the faint, cosmic hiss being recorded by
the SERENDIP IV SETI receiver on the world’s largest radio
telescope at Arecibo, Puerto Rico.
The receiver listens to data from random scans of the sky while
the giant, 305-meter dish goes about its other business. A part
of this data gets split up into “work units” and sent
to volunteers who have installed the SETI@home program on their
computers. Your computer analyzes these data whenever in screensaver
mode. It thrn sends back the results and fetches a new work unit
the next time you connect to the Internet. The whole process happens
very unobtrusively.
Version 3.0 widens the search to look for more complex signals.
The prior versions could recognize signals that drift in frequency
by up to 10 Hertz per second; this has been enlarged to 50 Hertz
per second, enough to catch signals emitted from a transmitter
in orbit around a planet or in some other fast orbit. The new
version also searches for pulsed signals (including “triplets”),
which alien radio astronomers might see as the most efficient
way to punch a noticeable signal across interstellar distances.
Since the project began in May 1999, the lab at the University
of California at Berkeley has created 63 million work units but
has sent out 202 million, including duplicates. The longer processing
times required by version 3.0 will put more of the army of volunteers
to productive use.
SETI@home was originally scheduled to end after analyzing two
years’ of recorded data. This is enough time for much of
the sky visible by the Arecibo telescope to be scanned at least
three times. But in August the Planetary Society (the project’s
founding sponsor) announced that it will finance a continuation
of the project into new areas beyond the original time limit.
“We’d like to cover more frequencies and more of the
sky,” says SETI@home chief scientist Dan Werthimer. Accordingly,
SETI@home plans to start analyzing data collected by a radio telescope
in the Southern Hemisphere starting in 2001, likely from the Southern
SERENDIP SETI project under way at the 64-meter Parkes dish in
Australia.