In a further breakthrough in the search for life-like planets capable of harboring life, the American space agency (Nasa) announced that its Kepler space telescope has confirmed for the first time the existence of a habitable planet outside the Solar System.
The planet Kepler 22b, first detected in 2009 and located about 600 light-years from Earth, is the first exoplanet confirmed by NASA as apt to harbor life.
Confirmation means that astronomers have seen him pass his star three times and that conditions for life are adequate in terms of water availability, temperature and atmosphere. But it does not mean that scientists really know if there is life there.
“We now have a positive confirmation of the planet Kepler 22b,” Bill Borucki, Kepler’s chief scientist at NASA’s Ames Research Center, told reporters.
“We are certain that it is in the habitable region and that it has a surface that should have a pleasant temperature,” he said.
Kepler 22b has 2.4 times the Earth’s radius, which places it in the group of planets called “superterrestrials”, and revolves around its own sun every 290 days.
Scientists calculate that their surface temperature is 22 degrees Celsius, but they do not know if the planet is rocky, gaseous or liquid. The first “passing” of the planet in front of its star was captured shortly after NASA launched the Kepler space telescope in March 2009.
NASA also announced that Kepler discovered another 1,094 possible exoplanets, twice as much as it had been traced, according to a study presented at a conference in California this week.
NASA’s Kepler mission is the first of the American space agency in search of planets like Earth orbiting stars similar to the Sun.
This $ 600 million space telescope is equipped with the largest camera ever sent into space and is expected to continue sending information to Earth at least until November 2012.
Kepler looks for planets as small as the Earth, including those that orbit stars in a warm, habitable region where liquid water may exist on the surface. With Kepler 22b are three exoplanets confirmed by scientists around the world capable of harboring life.
In May, French astronomers had already confirmed the first rocky exoplanet with key conditions to sustain life, the Gliese 581d.
In August, Swiss astronomers announced the discovery of another planet, the HD 85512 b, located 36 light-years away as potentially habitable.
However, these two planets are “orbiting smaller, colder stars than the Sun,” NASA said in a statement, noting that Kepler 22b “is the smallest so far found to orbit the center of the habitable zone of a similar star to our Sun “.
“We are thrilled with this. We need all telescopes to observe these (possible Earth-like exoplanets) so we can confirm as much as possible, “Natalie Batalha, a team of scientists at Kepler University at San Jose, told reporters.
A total of 48 exoplanets and exolutions would have the capacity to house life outside the Solar System of a total of 2,326 potential planets identified by the Kepler telescope, according to the classification of the Planetary Habitability Laboratory (PHL), University of Porto Rich in Arecibo.
The Habitable Exoplanet Catalog (HEC), available at http://phl.upr.edu, is the first to classify the exoplanets and the exolutions according to their habitability.
The rankings give scientists “the ability to compare exoplanets to better or worse candidates for life,” said Abel Méndez, director of the PHL and principal investigator of this project.