10 billion 'habitable' planets found
ONE out of every five sun-like stars in the Milky Way is orbited by a planet about the size of Earth where surface temperatures should be compatible with liquid water, a key ingredient for life, a study released on Monday showed.
The analysis, based on three years of data collected by Nasa's now-idle Kepler space telescope, indicates that the galaxy is home to 10 billion potentially habitable worlds.
The number grows exponentially if the count includes planets circling cooler red-dwarf stars, the most common type of star in the galaxy.
The research was published in this week's Proceedings Of The National Academy Of Sciences and presented on Monday at a Kepler science conference at Nasa's Ames Research Center in Moffett Field, California.