New Estimate for Alien Earths: 2 Billion in Our Galaxy Alone

Roughly one out of every 37 to one out of every 70 sunlike stars in the sky might harbor an alien Earth, a new study reveals. These findings hint that billions of Earthlike planets might exist in our galaxy, researchers added. After the researchers analyzed the four months of data in this initial batch of readings from Kepler, they determined that 1.4 to 2.7 percent of all sunlike stars are expected to have Earthlike planets — ones that are between 0.8 and two times Earth's diameter and within the habitable zones of their stars.
"This means there are a lot of Earth analogs out there — two billion in the Milky Way galaxy," 

"With that large a number, there's a good chance life and maybe even intelligent life might exist on some of those planets. And that's just our galaxy alone — there are 50 billion other galaxies." After three to four years of Kepler data are investigated, the scientists predict a total of 12 Earthlike worlds will be found. Four of these have already been seen in the four months of data released so far, they added. Kepler mission scientists have estimated that, altogether, there could be 50 billion planets in the Milky Way, though not all would be Earth-size worlds within the habitable zone of their local stars. Space.com