for National Geographic News
Do extraterrestrials sweep their skies with radar to scan for incoming missiles?
If so, Avi Loeb of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, thinks he can find the radio signals leaked from warring alien civilizations.
He might also be able to catch their version of reality TV and talk radio.
The concept is different than other radio programs in the search for extraterrestrial intelligence (SETI) that look for high-frequency signals deliberately beamed across space to make contact with distant civilizations.
Extraterrestrials may not emit such beacons, Loeb theorizes.
"However, our own civilization is transmitting power unintentionally through radio and TV broadcasting and military radars," he said in a videotaped presentation played Wednesday to reporters at a meeting of the American Astronomical Society in Seattle, Washington.
"An interesting question is whether we can eavesdrop on another civilization at the frequencies that we are ourselves transmitting in," he said.
(See related story: "Are Neighborhood Aliens Listening to Earth Radio?" [September 7, 2006].)
Loeb believes he can detect the leaked signals by piggybacking his search on a new generation of radio telescopes designed to study low-frequency radio emissions in the distant, infant universe.
He and his colleagues hope to test the theory with the Mileura Wild-Field Array currently under construction in Australia and is slated to start operations in 2008.
In its current configuration, the array will be sensitive to any Earth-like civilizations that may exist on a planet orbiting one of about a thousand stars up to 30 light-years away, Loeb said.
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