We know that there are other planets like earth in the galaxy that could possibly sustain life. There could be life somewhere on other planets. There are movies that even show life could be on other planets and not just ours. One movie that I know that has a species is Avatar. The movie Avatar shows how those aliens live and look like. In the movie it also said that the planet ,Pandora, was an Earth like planet. That means if you have the right gear because in the movie Avatar you need masks because the oxygen is much different than ours. If you find the right planet with a sun no too close but not to far you could just find that spot which could sustain alien life or plant life and human life if possible.