Read More: SETI Institute
Imagine this scenario: On a world orbiting a neighboring star, a society more advanced than our own has used large telescopes to survey all the planets within a few hundred light-years. In this sample of a million worlds, it finds that one percent show the tell-tale atmospheric gases that indicate life. One of these is Earth. This society is sufficiently distant that clues to the existence of Homo sapiens, in the form of high-powered radio signals, have yet to arrive. But their scientists know that Earth is laminated with biology of some kind. And so, simply as a wake-up call to any intelligence that might be here, they occasionally “ping” Earth with a short flash of laser light – the kind of signal that any technically competent species could recognize as artificial and deliberate. Such pinprick light flashes could be routinely dotting the heavens today, but we wouldn’t know. Most telescopes are insensitive to short light pulses, and in any case are focused on tiny patches of the sky. We would no more be aware of such signals than Columbus was of Jupiter’s moons, despite the fact that they were in plain sight. Plain, that is, with the right equipment. The SETI Institute has developed an instrument that, at relatively low cost, could continuously survey the entire night sky for brief laser pulses. This is completely unlike the optical SETI efforts that have been made in the past, and continue to be made today: experiments that use sensitive photomultiplier detectors, but are limited to one star system at a time. That’s akin to a radio SETI search able to only monitor a single frequency channel. Extremely limited.