“There are something like a few dozen solar-type stars within something like 30 light years of the sun, and I would think that a good number of those — perhaps half of them — have Earth-like planets,” says Alan Boss, an astrophysicist from the Carnegie Institution for Science.

“So I think there is a very good chance that we will find some Earth-like planets within 10, 20 or 30 light years of the Sun.”