[1]
“Kepler-452b artist concept [1]” by NASA – http://www.nasa.gov/image-feature/soaking-up-the-rays-of-a-sun-like-star-artistic-concept [2]. Licensed under Public Domain via Wikipedia [3].
July 23 2015 NASA announced that the Kepler space telescope had found the most Earth-like exoplanet yet:
The discovery [4] of a super-Earth-sized planet [Kepler-452b [5]] orbiting a sun-like star brings us closer than ever to finding a twin of our own watery world. But NASA’s Kepler space telescope has captured evidence of other potentially habitable planets amid the sea of stars in the Milky Way galaxy.
I think that the most impressive fact about exoplanets, including Earth-like, is that we had the imagination to believe that they had to exist, given such small empirical evidence (just one solar system).
This might be a fact of the Universe given the infinity of it on both scales (10 to the positive power and 10 to the negative power.
So there must be a lot of “Earths” out there, and we might have some better guesstimates on some of the factors of the Drake Equation [6] now.
Congratulations to us all with this amazing find, that was science fiction in my childhood!