Big news! Kepler-186f is the FIRST rocky Earth-sized exo-planet found! I am hoping this is just the first of a new series of discovery.
Being in the habitable zone means there is a possibility first of an atmosphere. If there is an atmosphere the similar Earth size then it could be possible to have an atmosphere more like our own. At the very least Hydrogen and Helium should be lacking as it is here, because as you know both of those gases are made of small and light atoms; those atoms move fast and at Earth temperatures, that velocity exceeds Earth’s escape velocity. Planets like Jupiter and the other gas giants have more gravity and are colder so Hydrogen and Helium are retained.
Then of course that only after an atmosphere you have to have the rest of the pieces. Or Kepler-186f could be just a big rock.
We are a long way from knowing the details on Kepler-186f, but just finding a planet of Earth size and in the habitable zone is an excellent start!
Here’s the press release from NASA (great wallpaper too!):
The artist’s concept depicts Kepler-186f , the first validated Earth-size planet to orbit a distant star in the habitable zone—a range of distance from a star where liquid water might pool on the planet’s surface. The discovery of Kepler-186f confirms that Earth-size planets exist in the habitable zones of other stars and signals a significant step closer to finding a world similar to Earth.