A least 17 billion Earth-like planets across the Milky Way: study Astronomers hunting for Earth-like planets now have many places to look. A new estimate released Monday suggested the Milky Way galaxy is home to at least 17 billion planets similar in size to our planet. It doesn’t mean all are potentially habitable, but the sheer number of Earth-size planets is a welcome starting point in the search for worlds like our own. “Earths and super-Earths aren’t picky. We’re finding them in all kinds of neighbourhoods,” co-author Guillermo Torres of the Harvard-Smithsonian Center for Astrophysics said in a statement. The CfA was one of two teams working on the project. (C. Pulliam & D. Aguilar (CfA))