Is Mars ours?

The more I have been looking at Mars, the more convinced I become that this is not our planet. Either people have been living there and possibly still are, or the planet is used by other civilizations. Perhaps as a surveillance or battle training station. In any case, it would be presumptuous to assume it is ours to do with what we wish. Maybe it's time to review the ethics around space exploration. I think the Star Trek prime directives are good guidelines. To not interfere in the development of civilizations and to acknowledge the rights of all sentient being to live according to their culture. However, we are not following those rules here on Earth, so we might begin with that. But, what do we do when a culture is considered harmful of other sentient beings? In Star Trek the prime directive is often set aside for the greater good of what is considered morally right according to human understanding, and equally often it is proven wrong, as the civilizations eventually show they have reason for what at first seemed to be illogical and unethical behavior. I guess we must be adaptable and open-minded to what we will find on Mars and not assume the planet belong to us. Let's aim for exploration before exploitation.