Computer Users are Helping Scientists Search for Extraterrestrial Signals from Space
By Robert Sanders, Public Affairs
One hundred lucky pioneers have gotten the chance of a lifetime - the opportunity to participate in a unique search for extraterrestrial intelligence from their desktop computers.
These one hundred are testing a one-of-a-kind computer program called SETI@home that allows a desktop PC to analyze radio data from space in search of intelligent signals. If all goes well, the finished product will roll out in April for 100,000-plus people who have already signed up to participate.
The computer program is essentially a screen saver that kicks in when your desktop computer is idle, and crunches data collected from a radio dish in Puerto Rico.
"SETI@home is a way of harnessing all the idle computers to increase our computing capacity and our chance of finding extraterrestrials," said SETI@home project scientist Dan Werthimer, a research physicist at the campus's Space Sciences Laboratory.
SETI@home - named after the acronym for the search for extraterrestrial intelligence, SETI - is a way for Berkeley's SETI physicists to more thoroughly analyze the data they receive daily from their ongoing survey of the sky using the large radio dish at Arecibo, Puerto Rico.
This 20-year-old search, which piggybacks on the Arecibo telescope, is called SERENDIP IV - the fourth incarnation of an instrument designed to Search for Extraterrestrial Radio Emissions from Nearby Developed Intelligent Populations.
"SETI@home does an exceptionally good job of analyzing a small band of signals very thoroughly," said Werthimer.
The radio data is broken down into small chunks, and a screen saver program searches for patterns that may indicate a deliberate broadcast from a distant civilization.
"You can download enough data through the internet in five minutes to keep the computer analyzing for several days," said computer scientist David Anderson, project director and a long-time volunteer with the project. "The computer then sends back a summary of the interesting stuff it found, and gets another chunk of data.
As the computer works away at the data, the computer screen displays a three-dimensional graph charting the signal analysis.
Anderson developed the screen saver program that crunches the data, now available only for PCs. He currently is developing versions for Macintosh, Unix, Linux and other systems.
The SETI@home project is the first "distributed computing" project to offer the general public the opportunity to participate in important research.
"Ours is the first that actually does a useful computation and sends data both ways through the pipe," Anderson said.
SETI@home has been building to this point for several years, mostly with the help of volunteers. What finally got it off the ground, however, was an infusion of money from the Planetary Society, which donated $50,000, and Paramount Studies, which donated another $50,000 and is tying the project to its new movie, "Star Trek: Insurrection," which launched Dec. 11. Sun Microsystems also has donated computer equipment to SETI@home.
SERENDIP records signals and stores them on magnetic tape, which is expressed to Berkeley for analysis.
Interesting signals turned up by SETI@home must be checked by people like Werthimer to make sure they are not due to radio interference from Earth or orbiting satellites.
"We're not asking people to call the press when they see a spike on the screen," Werthimer said. "We get strong signals all the time and have to sift through them."