Astronomers   say they are on the point of finding planets like Earth orbiting other stars, which is 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 sometime this year. 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 Dew Kepler telescope and a lot of new research from the suddenly hot and competitive exoplanet field caused noticeable buzz at the meeting.Scientists are talking about being at "an incredible special place in history" and closer to answering the question. "Are we alone? For the first time, there's an optimism that sometime in our lifetimes we're going to _ that," said Simon Worden,an astronomer who heads NASA's Ames Research Center. "If I were a betting man, which I am, I would bet we're not alone." "These are big questions that reflect upon the meaning of the human race in the universe," the director of the Vatican Observatory, the Rev. Jose Funes, said Wednesday in an interview at this week's conference. Worden told The Associated Press: "I would certainly expect in the next four or five years we'd have an Earth-sized planet in the habitable   zone." What's an exoplanet?
It's a planet like Earth It's a planet outside our solar system. It's a planet orbiting the sun It's a planet where life have developed.