Firstly, for any life to live on a planet the temperature has to be just right, (Not too hot nor too cold). Plus, for any life to exist elsewhere anyway, they would have to learn not to destroy themsleves with their own technology. Even if there is life out there, it could be tiny, or huge. Who knows? We will just have to wait until the future commences. We are pretty lucky to have a planet like we have now. But the future says the Sun will become a Red Giant, burning all planets in this galaxy up to Mars. That would of course destroy any life possibilities on Mars.
We will have to rely on thoses daring astronauts, or those great probes.