The Habitable Zone Not really so small

When you think about it, the only think keeping us warm or cool from the sun is our atmosphere, not really where we are located. We could probably be where Venus is right now and, if we had the right atmosphere be able to live there. But there is a limit to where we cna be. Obviously, there is no atmosphere strong enouph to support life where mercury stands, and pluto is so far away that it would not absorb enouph heat into the atmosphere, but this should tell us that planets we have found outside the solar system could sustain life if they have the right atmosphere. We do not know what their atmosphere is composed of entirely and where the planet is exactly, but we can't just say it doesn't support life bacause it is out of the "habitable zone."