New Search for Extra-terrestrial TV

"Soon, we may be eavesdropping on signals from Galactic civilizations," says theorist Avi Loeb of the Harvard-Smithsonian Center for Astrophysics. "This is the first time in history that humans will be capable of finding a civilization like ours among the stars."

Previous SETI programs would not have detected an Earth-like civilization. The searches often looked for beacon-like signals deliberately beamed across space. Such beacons may not exist. Also, most radio SETI projects examined frequencies higher than 1 Gigahertz in order to avoid interference from both Earth-based and natural cosmic sources.

Instead of looking for deliberate broadcasts, Loeb suggests looking for accidental leakage from an alien civilization. He points out that the new Low Frequency Demonstrator (LFD) of the Mileura Wide-Field Array (MWA), a facility for radio astronomy, will pick up the same frequencies used by Earth technologies. On Earth, military radars are the most powerful broadcast sources, followed by television and FM radio. If similar broadcast sources exist on other planets, facilities like MWA-LFD might detect them.

Loeb calculates that by staring at the sky for a month, the MWA-LFD could detect Earth-like radio signals from a distance of up to 30 light-years, which would encompass approximately 1,000 stars.

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