WASHINGTON — NASA's planet-hunting telescope has discovered two planets that seem ideal for some sort of life to flourish. And they are just the right size and in just the right place.
The distant duo are the best candidates for habitable planets that astronomers have found so far, said William Borucki, the chief scientist for NASA's Kepler telescope. And it's got astronomers thinking that similar planets that are just about right for life — "Goldilocks planets" — might be common in the universe.
The discoveries, published online Thursday in the journal Science, mark a milestone in the search for planets where life could exist. In the four years Kepler has been in orbit, the telescope has found 122 planets outside our solar system.
In the past, those planets haven't fit all the criteria that would make them right for life of any kind, from microbes to man.
In the Goldilocks game of looking for other planets like ours, the new discoveries, called Kepler-62-e and Kepler-62-f are just right.
The planets are slightly wider than Earth, but not too big. Kepler-62-e is balmy, like a Hawaiian world. Kepler-62-f is frosty, more Alaskan, Borucki said. The pair is 1,200 light-years away; a light-year is almost 6 trillion miles.
"This is the first one where I'm thinking 'Huh, Kepler-62-f really might have life on it'," said study co-author David Charbonneau of Harvard. "This is a very important barrier that's been crossed. Why wouldn't it have life?"