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. Last Updated: 07/27/2016

Home PCs Aid Search for Aliens

The truth is out there -- and scientists hunting for extraterrestrial life want your PC to help find it.

Astronomers have spent decades listening to the heavens on powerful radio telescopes, waiting for signs that we are not alone. Their effort, known as the Search for Extraterrestrial Intelligence, or SETI, was celebrated in the Jodie Foster film "Contact."

Now SETI researchers in California have developed an innovative scheme to yoke together thousands of idle home PCs and turn them into a virtual supercomputer to intensify the hunt.

Their tool is a screen saver. But instead of displaying flying toasters or some other digital doodads when your computer is idle, this screen saver plucks raw data off the Internet from SETI radio telescopes and combs it for signs of E.T. phoning home.

The software, known as SETIhome, will be available free on the Internet in April. It offers computer owners a rare chance to participate in a real scientific mission - and the minute but tantalizing possibility their PC will be the one to detect the first faint murmur of a civilization beyond Earth.

"It's a chance to help answer an age-old question: Are we alone?" says project scientist Dan Werthimer of the University of California, Berkeley. "And it's better than watching flying toasters."

Life on other planets is still the stuff of science fiction - but it is looking more plausible to scientists every day.

For example, the National Aeronautics and Space Administration recently established an "astrobiology" institute to study life in the universe, and scientists are seriously debating whether a Martian meteorite found in Antarctica holds fossils of primitive alien life. In the past two years, astronomers have discovered what appear to be 12 planets orbiting other stars, the first evidence of planets outside our solar system.

The screen-saver project will get a splashy send-off from Paramount Pictures, which promotes the project via its new "Star Trek" flick. The studio thought the Star Trek gestalt - "to seek out new life and new civilizations" - was a perfect fit and pitched in $50,000 to help get the SETIhome program running.

Next month, organizers will begin a limited test of the screen-saver software, and in April they'll make it available on the Internet to anyone who signs up. So far 110,000 people have volunteered. "We're hoping this will not just appeal to nerds and Trekkies but school kids, and that teachers make it part of their curriculum. After all, SETI touches on astronomy, biology, chemistry and evolution - all the fundamental questions of life," Werthimer says.

SETIhome will use data collected by the world's largest "ear," the 1,000-foot-wide Arecibo radio telescope nestled in the Puerto Rican jungle. The collection equipment is designed to listen to 168 million frequencies simultaneously and sweep the entire visible sky every three to six months.

There's a lot to hear because the universe is not a quiet place. Stars belch and hiccup photons into the cosmos, and these intergalactic emanations can be heard by radio telescopes here on Earth.

Humans also contribute to this universal jazz. Every radar signal, radio show and TV program ever broadcast - from "I Love Lucy" to the "X-Files" - is now zipping through space. Since radio waves travel at the speed of light - 299,792.5 kilometers per second - older broadcasts have whipped past a few thousand stars. Even now, some alien civilization orbiting star Gliese 623b could be puzzling over "Planet of the Apes" and forming a very misguided impression of us. Or the apes.

At the same time, radio waves broadcast by other civilizations may be bombarding our living rooms.

Over the years there have been more than 60 serious attempts to find radio evidence of intelligent life - patterns of signals that stand out from the chaos of the universe. So far, they've heard not a bleep.

One problem is figuring out where to look. The electromagnetic spectrum is technically infinite. Even if the search were limited to radar, television and radio signals, it would mean, as astronomer Carl Sagan might have put it, billions and billions of frequencies to pore over.

The powerful computers that SETI uses to analyze these signals aren't up to the job. As a result, much of the data they collect gets a quick once-over and is trashed. Scientists worry that buried somewhere in the garbage is the greatest discovery in the history of humankind. "SETI is limited by how much computer power is available to it," project director David Anderson says. "There's a lot of types of signals that we miss."

By tapping the horsepower of home computers around the globe, scientists say they'll be able to dig for fainter signals and more subtle patterns.

Volunteers will, in essence, get their own little piece of the sky to chew on. A central computer at Berkeley will divvy up data from the Arecibo telescope into 250,000-byte chunks. It will automatically parcel out that data to home computers through the Internet, typically when participants log on to check e-mail or surf the web. The transfer should take a few minutes, even with a standard modem connection.

Like a normal screen saver, SETIhome will kick in whenever the computer sits idle for a few minutes, sifting through the raw astronomical data for unusual signals, weeding out natural celestial noise and Earth-generated buzz.

"Terrestrial pollution is a big problem. It's getting harder and harder to do these kinds of searches," Werthimer says. "Military radar and television signals are just blasting us."

When the analysis is complete - anywhere from a few days to weeks later, depending on the computer's speed and how often it's available - the results will be transmitted back to SETI and a new slice of sky will be dished out.

If a potential alien signal is discovered by a home computer, it will be analyzed in Berkeley and then by a SETI team elsewhere for independent confirmation.

"You may become super-famous and share a Nobel Prize. But I wouldn't hold my breath," says Werthimer, who has been searching the sky for two decades without finding a signal worthy of a second look.

"Earthlings are just learning how to do this - we've only had radio for a hundred years," he says. "I think we would be lucky to find another civilization right now. But I know someday we will."

The SETIhome web site is