Top 5 Habitable Alien Planets - here we have examples of planets located within the habitable zone, for just one star. There are billions of stars out there. So the idea of the non-existence of extra-terrestrial intelligent to be highly absurd.
Kepler-22b is an extrasolar planet orbiting G-type star Kepler-22. It is located about 600 light years from Earth in the constellation of Cygnus. It was discovered by NASA's Kepler Space Telescope in 2011 and was the first known transiting planet to orbit within the habitable zone of a Sun-like star.