In another step toward finding Earth-like planets capable of supporting life, the U.S. space agency NASA announced on Monday that the Kepler space telescope first confirmed the existence of a habitable planet outside our solar system.
Kepler 22b, first detected in 2009 and located about 600 light years from Earth, is the first exoplanet confirmed by the U.S. space agency as suitable for life.
Confirmation means that astronomers saw him pass in front of its star three times and that the conditions for life are adequate in terms of water, temperature and atmosphere. But it means that astronomers know for sure that there really is life there.
"Now we have positive confirmation of Kepler 22b planet," he told reporters Bill Borucki, Kepler principal investigator at Ames Research Center NASA.
"We are confident that it is in the habitable zone and that has a surface temperature should have a nice," he said.
Kepler 22b is 2.4 times the radius of the Earth, which includes it in the group of planets called "superterrestres" and revolves around a star similar to the Sun every 290 days.
Scientists estimate that its surface temperature is 22 degrees Celsius, but do not know if the planet is rocky, gaseous or liquid.
The first "passage" of the planet facing its star was caught shortly after NASA launched its Kepler space telescope in March 2009.
NASA also announced that Kepler has discovered other possible exoplanets 1094, double the number who had been tracking, according to a study presented at a conference in California this week.
Kepler is NASA's first mission seeking Earth-like planets orbiting Sun-like stars
The space telescope, which cost NASA about $ 600 million, is equipped with the largest camera ever sent into space and is expected to continue sending data to Earth until at least November 2012.
Kepler looks for planets as small as Earth, including those that orbit stars in a warm and habitable where liquid water could exist on the surface.
With Kepler exoplanet 22b are three confirmed by scientists around the world that could support life.
French astronomers had confirmed in May and the first rocky exoplanet qualifying key to sustaining life, Gliese 581d.
In addition, Swiss astronomers reported in August from another planet, HD 85 512 b, located about 36 light years away, as potentially habitable.
However, these two planets "orbiting stars smaller and cooler than the Sun," NASA said in a statement, noting that Kepler 22b "is the smallest found to date that orbits the center of the habitable zone of a star similar to our Sun. "
"We are excited about this. We need all the telescopes observe these (possible Earth-like exoplanets) so we can confirm as much as possible, "he told reporters Natalie Batalha, the Kepler team of scientists at the University of San Jose.
A total of 48 exoplanets and would exomoons capacity for life outside the solar system, among a total of 2326 potential planets identified by Kepler according to the classification of Planetary Habitability Laboratory (PHL, for its acronym in English) at the University of Puerto Rico at Arecibo.
Habitable Exoplanet Catalogue (HEC), available online at http://phl.upr.edu, is the first exoplanet and exomoons classify according to their habitability.
The rankings give scientists "the ability to compare best to worst exoplanet candidates for life," said Abel Mendez, director of PHL and principal investigator of this project.