Listening for ET

Are we alone in the Universe? We won’t know until we really start looking for life around other stars… or listening for it.

Astronomers from the Harvard-Smithsonian Center for Astrophysics are proposing a new method that could detect Earth-like civilizations around the 1,000 nearest stars.

Previous searches for extraterrestrial intelligence, or SETI, have assumed that the aliens want us find them. The searchers have looked for a focused signal from another star. Instead, this new survey would look for the accidental leakage from an alien civilization. In other words, we’d be listening in on their television broadcasts, FM transmissions, or military radars.

One instrument that might do the trick is the Mileura Wide-Field Array, which is being built in Australia. It could be powerful enough to pick up a transmission from within a 30 light-year radius – containing 1,000 stars. An even more powerful radio observatory, like the Square Kilometer Array, could pick up broadcasts within 10 times the radius. This would encompass a volume containing 100 million stars.