Study: One in Five Milky Way Stars Hosts Potentially Life-Friendly Earths

Photo Credit: Reuters/NASA Ames/JPL-CaltechOne out of every five sun-like stars in the Milky Way galaxy has a planet about the size of Earth that is properly positioned for 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-idled Kepler space telescope, indicates the galaxy is home to 10 billion potentially habitable worlds.

The number grows exponentially if the count also includes planets circling cooler red dwarf stars, the most common type of star in the galaxy.

“Planets seem to be the rule rather than exception,” study leader Erik Petigura, an astronomy graduate student at the University of California at Berkeley, said during a conference call with reporters on Monday.

Petigura wrote his own software program to analyze the space telescope’s results and found 10 planets one- to two-times the diameter of Earth circling parent stars at the right distances for liquid surface water.