"Searching for EARTH 2.0" [2014 Documentary]

Habitable alien planets similar to Earth may not be that rare in the universe, a new 2014
study shows one in five sunlike stars observed by NASA's planet-hunting Kepler spacecraft has an Earth-size planet in the so-called habitable zone, where liquid water and, potentially life could exist, according to the new study. If these results apply elsewhere in the galaxy, the nearest such planet could be just 12 light-years away."Human beings have been looking at the stars for thousands of years".

How many of those stars have planets that are in some way like Earth?

As requested (HD version): https://www.youtube.com/watch?v=5E6WV...