Research Projects and SIG SETI@Home Version 3.0 This email from seti@home was forwarded by Matt Oltersdorf on October 7, 2000 SETI@HOME EXPANDS The SETI@home project released a major upgrade this week in its quest to scan the sky for signs of intelligent life in the universe. Some 2.4 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 (a 2.5-megahertz-wide band centered on the 1,420-MHz frequency emitted by hydrogen atoms) gets split up into "work units" and sent to volunteers who have installed the SETI@home program on their computers. Your computer analyzes this data whenever idling in screensaver mode. When it's done, it 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 Hz per second; this has been enlarged to 50 Hz 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. The program's math efficiency has also been optimized, so that even with the additional processing, a work unit should take only about 40 percent longer to complete -- in other words, anywhere from about 10 to 80 hours of processing time, depending on your computer. Users may notice more variation in the time that individual work units require. The longer processing time will go a little way toward solving an embarrassing problem for the SETI@home project: an embarrassment of riches. Of the 2.4 million people who have downloaded the software, about 1.4 million have followed through and returned results from at least one work unit. Some 500,000 currently qualify as "active users," having returned at least one result in the last two weeks. This amounts to about four times more processing power than the project has needed. Data is recorded at Arecibo at a rate of about 150,000 work units per day, but during the last two months the SETI@home lab has sent out an average of 615,000 work units per day to meet the volunteers' demand. The difference is made up by sending out duplicates as make-work. 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. A likely source for this data will be the Southern SERENDIP SETI project under way at the 64-m Parkes dish in Australia. Parkes can scan most of our Milky Way galaxy's enormous volume _ unlike Arecibo, which can point only near Puerto Rico's zenith. "We will also continue to use Arecibo, but maybe on other [frequency] bands," says Werthimer.   Return to Research and SIG Seti@home Return to Research Return to SIG