When I first began to work on Quest's SETI: The Search for ET segment, I have to admit that my initial reaction was "are we still looking for ET?" Of course, humans have been gazing up to the heavens for millennia, asking ourselves that interminable question "are we alone?" And of course, there's been a long line of increasingly sophisticated radio telescopes searching the skies for cosmic signs of intelligence. But hey, don't we at some point have to call it a day? Though I think most of us don't actually believe we're alone, the universe is really, really big. What chance do we have of finding ET?
Well, it turns out our chances are much better than I thought. Grote Reber began conducting sky surveys in the radio frequencies with his newly invented radio telescope in 1937, and detected the first signals from outer space in 1938. In the seven decades since then, we've seen a multitude of radio telescope designs pop up all over the world, but we still haven't gotten signals from any little green men. What I didn't understand, until I spoke to Jill Tarter and Seth Shostak at the SETI Institute, is that in all that time, we've hardly looked at any space at all.
Since SETI's first experiment in 1960 by Dr. Frank Drake, and until very recently, they've only looked at a thousand stars out of about 400 billion stars in our galaxy, and there are 100 billion other galaxies to look at! There are two reasons for this: 1) The radio telescopes they've been using can only look at narrow swaths of the sky, and 2) they've had to RENT time on other people's telescopes, which constrains their search and budget. Now, the new Allen Telescope Array is being built just for them, and with it they'll be able to capture millions of frequencies from multiple star systems simultaneously. It will be the biggest and fastest tool in the world for seeking signs of ET!
To learn why scientists use radio frequencies in the hunt for intelligent life, and to learn more about the history & future of the search, watch our story SETI: The Search for ET. You can also watch our extended interview with Astronomer Jill Tarter. And hey folks, the SETI Institute is a non-profit organization, so if you'd like to help them out with the search, consider adopting a scientist like Jill Tarter or Seth Shostak. Go to Adopt-a-Scientist, or join Jill's team and become a TeamSETI member at Join TeamSETI.
Also, check out U.C. Berkeley’s SETI@home page and turn your home computer into a tool that downloads and analyzes radio telescope data.