[troutman]

Originally Posted by CorsiHockeyLeague

But this only applies to the observable universe. For obvious reasons, we cannot observe whether this is true of regions outside of the observable universe.

Kepler's planet survey indicates that Earth-sized planets in a star's habitable zone, the perfect distance that could allow water to pool on the surface, are ubiquitous in our galaxy. Based on the survey, scientists predict that there should be 1 billion Earth-sized worlds in the Milky Way galaxy at present, a good portion of them presumed to be rocky. That estimate skyrockets when you include the other 100 billion galaxies in the observable universe.