spacetoday.net: Study: Milky Way may have billions of potentially Earth-like planets

Posted: Tue, Nov 5, 2013, 5:45 AM ET (1045 GMT)
Kepler spacecraft illustration (NASA/Ames)

More than 20 percent of the Sun-like stars in the Milky Way galaxy may have Earth-sized planets orbiting in those stars' habitable zones, astronomers announced Monday. An analysis of Kepler data by a team at the University of California Berkeley detected 10 potentially Earth-like planets, based on their size and amount of starlight they receive, in a sample of 42,000 stars. Correcting for observing geometry and stellar variability to account for planets Kepler can't detect, the team concluded that about 22 percent of Sun-like stars have such planets in their habitable zones, or billions of such planets in the Milky Way alone. While such planets could potentially be hospitable to life, scientists note they don't have the ability to determine which ones are, in fact, habitable.