- A planet has been found in the "habitable zone" -- a region where liquid water could exist.
- The newly confirmed planet, Kepler-22b, is the smallest yet found to orbit in the habitable zone of a star similar to our sun.
- Previous research hinted at the existence of near-Earth-size planets in habitable zones, but confirmation had been elusive.
A planet about twice the size of Earth has been confirmed to exist right in the middle of the "habitable zone" around its star, which is much like our own.
Previous research had hinted at the existence of such Earth-like planets, where liquid water could exist, but this is the first time such a life-friendly alien planet has been confirmed.
The planet, known as Kepler-22b, is among 29 confirmed and 2,326 candidate worlds found by a team of astronomers using NASA's Kepler Space Telescope.
Kepler-22b is the smallest planet yet to be found beyond our solar system in the region most conducive to life as we know it on Earth.
"If the greenhouse warming was similar on this planet and if it had a surface, its temperature would be something like 72 degrees Fahrenheit, a very pleasant temperature here on the Earth," William Borucki, lead Kepler researcher at NASA's Ames Research Center in Moffett Field, Calif., said at a press briefing Monday.
The planet is around 2.4 times wider than Earth -- making it a "super-Earth." It takes 289.9 days to fly around its parent star, which is very much like our sun.
"It's almost a solar twin," Batalha said.
More work is needed before scientists will be able to tell if Kepler-22b is rocky like Earth, gaseous like Neptune, or more probably, a mix. But its discovery is a milestone on the road to finding bona fide Earth-like planets.
"We don't know anything about the planets between Earth-size and Neptune-size because in our solar system we have no examples of such planets," said Natalie Batalha, Kepler deputy science team lead at San Jose State University.