In the search for Earth-like planets, astronomers zeroed in on two places that look awfully familiar to home. One is close to the right size. The other is in the right place. European researchers said they not only found the smallest exoplanet ever, called Gliese 581 e, but realized that a neighboring planet discovered earlier, Gliese 581 d, was in the prime habitable zone for potential life. "The Holy Grail of current exoplanet research is the detection of a rocky ...

Astronomers unveiled Tuesday the lightest exoplanet ever detected and, in the same distant solar system, the first "serious candidate" for a world with abundant liquid water, both conditions essential for supporting life. "I would put the two discoveries on an equal footing," said Thierry Forveille, an astronomer at the Grenoble Observatory in France and a co-author of the study. "The holy grail of exoplanet research is to find a planet that combines both, the approximate mass of Earth and conditions favourable for water. Here we have each separately, but we ...

NASA's planet-hunting telescope, Kepler, rocketed into space Friday night on a historic voyage to track down other Earths in a faraway patch of the Milky Way galaxy. It's the first mission capable of answering the age-old question: Are other worlds like ours out there? Kepler, named after the German 17th century astrophysicist, set off on its unprecedented mission at 10:49 p.m., thundering into a clear sky embellished by a waxing moon. "It was ...