Optical Search

• The Nickel Telescope is used for this research. Photo by Laurie Hatch.

Using a triple photometer on the Nickel telescope, OSETI astronomers look for evidence of artificially-produced bursts of light which might indicate extraterrestrial intelligence.

Only one billionth of a second in duration, these light bursts would be created by other civilizations explicitly to signal distant intelligent life. All visible wavelengths are monitored. Three beams are recorded simultaneously to virtually eliminate false positive signals due to interference such as a cosmic ray or atmospheric instability.

Use of a triple photometer eliminates many false positive signals. The larger the photon pulse, the greater the chance it was not an accidental coincidence, but rather an intentional extraterrestrial signal. If the photon event is seen in only one or two detectors, researchers ignore it as a false positive. If researchers see a photon flux large enough to trigger all three detectors within the same one-billionth of a second, only rarely would this be a false positive. When observed in all three detectors, a signal is more likely to be an intentional one, which merits the time and effort necessary to make a confirming observation.

In conjunction with observatories throughout the world, Lick OSETI researchers target all stars with a presumed lifetime long enough to allow evolution of complex life. No lasers have been detected to date.