Tens of billions of potentially habitable, Earth-size planets in our galaxy

From KurzweilAI:

One in five stars in our galaxy like the Sun have planets about the size of Earth and a surface temperature conducive to life, astronomers at UC Berkeley and University of Hawaii, Manoa now estimate.

The estimate was based on a statistical analysis of all the Kepler observations of NASA’s Kepler space telescope of the 200 billion stars in our galaxy. Given that about 20 percent of stars are Sun-like, the researchers say, that amounts to several tens of billions of potentially habitable, Earth-size planets in the Milky Way Galaxy. “When you look up at the thousands of stars in the night sky, the nearest Sun-like star with an Earth-size planet in its habitable zone is probably only 12 light years away and can be seen with the naked eye. That is amazing,” said UC Berkeley graduate student Erik Petigura, who led the analysis of the Kepler data.

More here.