SETI@home: Why the Search for E.T. Needs Your Computer

Careening through outer space in a nearly solo search for aliens and adventure may be a norm in science fiction, but today, searches for alien life are decidedly earthbound—slow and collaborative. Since 1999, scientists at the Space Sciences Laboratory at the University of California at Berkeley have relied on volunteers to run software that analyzes radio signals in hopes of finding E.T. Called SETI@home, the search for extraterrestrial intelligence and the world’s largest distributed computing effort is making a “local” call for even more volunteers. They’re needed to handle the flood of data that upgrades to the project’s radio telescope have unleashed.

More on SETI

If you’d like to participate in SETI@home, visit the project’s website to learn more.

Why do we analyze radio signals to look for E.T.? And what exactly are they? Learn more.

SETI@home relies on radio signals detected by the world’s largest radio telescope, which fills a valley in Arecibo, Puerto Rico. An ordinary telescope sees visual images; in contrast, a radio telescope “sees” radio waves emitted by sources from anywhere in the universe, such as stars and other celestial objects—or aliens, if they’re out there. The problem is that there are plenty of radio waves being “seen” by the telescope (including interference of the radio waves we on Earth generate).

Since 1992, SETI scientists, led by chief scientist Dan Werthimer, have been recording signals from space and analyzing them for patterns that would indicate they were sent by intelligent life. But when the growing avalanche of data overwhelmed the ability of scientists to analyze it, David Gedye, then a graduate student at Berkeley, proposed using a virtual supercomputer made of large numbers of Internet-connected computers. In May 1999, SETI@home was officially launched.

Through a software program that is set to run during screensaver mode, scientists can tap the power of thousands of computers throughout the world. Today, SETI@home boasts the largest community of dedicated users of any Internet computing project: 170,000 people run the program on 320,000 computers. Some users even run the SETI on hundreds of computers they have access to, says project scientist Eric Korpela.

But now that the 1,000-foot-diameter Arecibo telescope has become 500 times more powerful with more sensitive receivers and more frequency coverage, the amount of data generated will amount to 300GB per day, or 100 terabytes (100,000GB) per year. That’s about the amount of data stored in the U.S. Library of Congress, says Korpela.

And that means new volunteers are crucial for keeping up with all that data.

So far, SETI@home has not found intelligent life beyond Earth, but scientists and devotees believe that’s only because the search—in comparison to what’s possible—is just getting started. “We’ve looked at a lot of stars, but we’ve surveyed only a tiny fraction of the whole galaxy,” says Korpela. “With the new receiver, we’re able to see about 500 times deeper into space and based on that alone, we’re 500 times more likely to find E.T. if he’s out there.”