Quest to find life beyond Earth gets technological boosts
And with new spacecraft to locate planets circling nearby stars, as well as more effective listening devices here at home, scientists have more tools at their disposal to find Earth-like planets or signs of other life forms.
But the possibility of intelligent life is what interests scientists at SETI. Using SETI’s 42-antenna Allen Telescope Array in Northern California, they can listen in many directions for unusual radio signals coming from space.
According to institute astronomer Seth Shostak, Carl Sagan posited that more than a million civilizations might be capable of broadcasting signals. Scientist and author Isaac Asimov hypothesized that the number might be half that. SETI astronomer Frank Drake has estimated the number might be closer to 10,000.