Astronomers find most Earth-like planets yet

Using a potent Nasa space telescope to scan the skies for planets like ours where life might exist, astronomers said Thursday they have found the most Earth-like candidates yet.
Two of the five planets orbiting a sun-like star called Kepler-62 are squarely in what astronomers call the habitable zone -- not too hot, not too cold and possibly bearing water, researchers said in the journal Science.
"These two are our best candidates that might be habitable," said William Borucki, Kepler science principal investigator at Nasa's Ames Research Center.
The two planets are slightly larger than ours, and at least a couple of billion years older.
Both are orbiting a seven-billion-year-old star some 1,200 light years from Earth in the constellation Lyra.
They are close enough to their star to be warm, but not so near as to boil the oceans. They are far enough to maintain the likelihood of water without freezing the seas solid, Borucki explained.
However, scientists do not yet know if their surfaces are rocky or watery, or if they have atmospheres that could sustain life.
"These are the most similar objects to Earth that we have found yet," said Justin Crepp, assistant professor of physics at the University of Notre Dame.
In late 2011, Nasa confirmed its first-ever planet in a habitable zone outside our solar system -- Kepler 22b, spinning around its star some 600 light years away.