The now-retired Kepler spacecraft has revealed that 1 in every 5 sun-like stars has an Earth-sized planet orbiting within the habitable zone. So breaking it down—when you look up at the sky, you can see the closest sun-like star with an Earth-size exoplanet with the naked eye because it’s only 12 light years away. NASA says the fact that 1/5 of all stars like our sun have a potentially habitable planet is an important find because the distance of these planets from us will influence the size and kind of telescope astronomers build to replace the now-defunct Kepler telescope. But remember these planets are only “potentially” habitable; we still have to consider whether they have a thick enough atmosphere and liquid water to support life.
[ Read the Article: Habitable, Earth-Sized Planets Believed To Orbit One-Fifth Of All Sun-Like Stars ]