Time flies. I remember writing an article here about the new idea of volunteer virtual supercomputers, pioneered by the people at SETI at Home. SETI stands for Search for Extraterrestrial Intelligence, and it was born out of the Space Race time’s vision of a universe full of spaceships and super-techological interplanetary empires. The idea, popularized by Carl Sagan, was to listen for radio signals from extraterrestrial civilizations.
If only we could listen with enough computing power, SETI’s proponents said, we will hear the sounds of extraterrestrial civilizations – if they exist. So, we’ve been listening, for years, and with a great deal of computing power too, thanks to SETI at Home.
SETI at Home uses home computers during their idle time to conduct statistical analysis of information collected by radio telescopes. With many computers sorting through the data, greater areas of the night sky could be listened to, and so, there would be a greater chance of picking out an extraterrestrial signal from the clutter. As large numbers of people joined SETI at Home, there was a feeling that an extraterrestrial signal might be found at any time.
That was almost 10 years ago. The 10-year anniversary of SETI is this May. Still, no extraterrestrial signals have been found.
Maybe it’s time to conclude that the extraterrestrial radio signals are not out there to be found. That could be because there are no extraterrestrials, or because there are no intelligent extraterrestrials, or because there are no intelligent extraterrestrials that use radio signals for communication.
It could be, of course, that we just haven’t looked for long enough. Space is extremely big, after all. If extraterrestrial life is common, extraterrestrial civilizations might still be uncommon, and something uncommon in something as large as the universe would be very difficult to find – something like searching for one green fish in an ocean full of yellow fish.
This is the International Year of Astronomy, and there’s a lot going on for astronomy buffs to celebrate – including stuff for astronomy buffs interested in extraterrestrial life.
The discovery of extrasolar planets has become commonplace, but astronomers are still honing the techniques they need to locate relatively small planets like our own orbiting stars other than our Sun. The smallest extrasolar planet yet discovered was located quite recently – announced just this month, as a matter of fact.
In less than a month, NASA will launch Kepler, a space telescope with the mission of locating Earth-sized planets around far away stars in our Galaxy.
Is it worth continuing the search, even though we haven’t heard from ET? You bet it is. We can find many new things other than extraterrestrials through the search. The time for faith in a universe full of intelligent extraterrestrial life, however, is over.