TV, radio waves to eavesdrop on ETs
TV and radio waves to eavesdrop on ETs.india Updated: Jan 17, 2007 14:14 IST
If extra-terrestrials were to sweep their skies with radar to scan for incoming missiles, then Avi Loeb of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts could possibly find the radio signals leaked from warring alien civilizations, or so he thinks.
According to him, the concept is different from other radio programs in the Search for Extra-Terrestrial Intelligence (SETI) that look for high-frequency signals deliberately beamed across space to make contact with distant civilizations, as extra-terrestrials possibly never emit such beacons.
"However, our own civilization is transmitting power unintentionally through radio and TV broadcasting and military radars. An interesting question is whether we can eavesdrop on another civilization at the frequencies that we are ourselves transmitting in," said Loeb in a video-taped presentation at a meeting of the American Astronomical Society in Seattle, Washington recently.
Loeb believes it is possible to detect the leaked signals by piggybacking the search on a new generation of radio telescopes designed to study low-frequency radio emissions in the distant, infant universe.
Now his team plans to test the theory with the Mileura Wild-Field Array currently under construction in Australia that 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,” National Geographic quoted Loeb as saying.
Loeb and his team are now of the opinion that future observatories, such as the Square Kilometer Array proposed for development in Australia or southern Africa, could detect Earth-like planets ten times farther away, which would encompass 100 million stars.
In such a scenario, detection of a radio emission from a distant planet could also guide other observatories to home in on to the source, Loeb said.
"That by itself would allow us to decide whether there could be liquid water on the surface of the planet and whether that can support life as we know it," he added.