I believe that extra-terrestrials do indeed live somewhere in this universe, other than earth. Do I know of it is intelligent life? No, no I don't. Sadly.
PSHHH. Well considering other planets atmospheres like earths, which are terrestrial planets inside the asteroid belt, are quiet similar but Venus is similar to earth inside and mass but its the hottest planet in our solar system. Mercury is too hot for life and Mars is possible if it had Oxygen and it does have frozen ice caps of H2O. Yet the other planets have more gaseous atmospheres different than earths. So those are too not likely support life either.