An international team of astronomers using the Kepler satellite has found two planets whose size and position suggest they may support life.
The planets orbit a star about 2,000 light-years away named Kepler-62 at the right distance for liquid water and, thus, life to exist, according to research published online by the journal Science.
Compared with Earth, the planets, named Kepler-62e and Kepler-62f, are larger and receive 0.41 and 1.2 times the amount of solar radiation. The planet hunters, led by William Borucki of the U.S. National Aeronautics and Space Administration, say they won’t know what the heavenly bodies look like or if they are in fact habitable until they can further analyze their atmospheres.
“We have found two planets in the habitable zone of another star, and they are the best planets found to date” that may support life, said Borucki, a space scientist at NASA’s Ames Research Center in Moffett Field, California.
One of the planets, Kepler-62f, may be a rocky celestial body with polar ice caps, Borucki said. The other, Kepler-62e, is believed to be warm and have lightning. While it’s too soon to know for sure, it may even be a water world, the first of its kind discovered, Borucki said.
“Kepler-62e probably has a very cloudy sky and is warm and humid all the way to the polar regions,” Dimitar Sasselov, an astronomer at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, and a co-author on the paper, said in a statement yesterday announcing the discovery. “Kepler-62f would be cooler, but still potentially life-friendly.”
The planets were discovered using NASA’s Kepler satellite, a spacecraft launched in 2009 with a mission to discover Earth-size and smaller celestial bodies in regions around their stars, particularly those where liquid water may exist. The spacecraft was launched in March 2009 and has found more than 2,700 planet candidates.
Kepler detects planets that cross the face of their stars, and gathers data that enables astronomers to estimate the sizes and make suggestions about composition.
The Kepler planets have 1.41 and 1.61 the radius of the Earth, according the researchers. Both planets may be solid, with either rocky or icy compositions, the scientists said.
In 2011, the Kepler mission found its first planet in the habitable zone, called Kepler-22b. That planet is larger than Earth, and orbits a sun-like star every 290 days.