Astronomers say they are on the verge of finding planets like Earth orbiting other stars, a key step in determining if we are alone in the universe.
A top NASA official and other leading scientists say that within four or five years they should discover the first Earth-like planet where life could develop, or may have already. A planet close to the size of Earth could even be found this year if preliminary hints from a new space telescope pan out.
At the annual American Astronomical Society conference this week, each discovery involving so-called "exoplanets" - those outside our solar system - pointed to the same conclusion: Quiet planets like Earth where life could develop probably are plentiful.
NASA's Kepler telescope, launched in March, and a wealth of new research from the suddenly hot and competitive exoplanet field generated noticeable buzz at the convention. Scientists are talking about being at "an incredible special place in history" and closer to answering a question that has dogged humanity since the beginning of civilization.
"The fundamental question is: Are we alone? For the first time, there's an optimism that sometime in our lifetimes we're going to get to the bottom of that," said Simon "Pete" Worden, an astronomer who heads NASA's