Ten Billion Earths . ... Credit Copyright: NASA / Ames / JPL-Caltech Explanation: How common are Earth-sized planets? ... Current computer models are indicating that at least one in ten stars are orbited by an Earth-sized planet, making our Milky Way Galaxy the home to over ten billion Earths. ... The number of Sun-like stars with Earth-like planets in Earth-like orbits is surely much less, but even so, Kepler has also just announced the discovery of four more of those. ... NASA Official: Jay Norris. ...