You might have wondered, looking up at the night sky, how many other beings are out there looking back at us. Help is at hand. Using data from NASA’s Kepler Space Telescope, New Scientist has made an interactive map illustrating the stars that we might expect to host roughly Earth-sized, potentially habitable planets.

Take a journey through space: Discover how many Earths

The grid of squares to the right represents the patch of sky that Kepler stared at for nearly four years. So far, the space telescope – nicknamed the Planet Hunter – has confirmed the existence of 151 exoplanets and identified more than 3500 strong candidates.

Now, using what we know from Kepler, and simulations from its data by Courtney Dressing and David Charbonneau of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, New Scientist has estimated and mapped the density of habitable worlds across the whole sky. Given that the Milky Way is thought to contain between 100 and 200 billion stars, our best estimate of the total number of such planets in our galaxy is 15 to 30 billion.


“This illustrates the wow factor emerging from the Kepler mission,” says Jon Jenkins of the SETI Institute in Mountain View, California, who wrote the software that analyses the Kepler data. “The galaxy is just full of potentially habitable planets.”

How many of these worlds harbour life? We don’t know, but if we are alone in our galaxy, it’s not for a lack of accommodation.