An Astronomical Discovery: Earth-Size Planet Found in Its Star's Habitable Zone

I have some cautiously exciting exoplanets news: Astronomers have announced the discovery of a planet that is very nearly the same size as Earth and orbiting its star in the habitable zone--that is, at the right distance from its star to have liquid water on its surface. We don't know how Earth-like it is, but this shows that we're edging closer and closer to finding another Earth, and this one is the best bet we've found so far. The planet is called Kepler-186f and was discovered using the Kepl...