With rounds of pioneering space flights that could set the stage for future space tourism，it is worth looking at what might be involved for the human exploration of Mars，though it's likely decades away. Technological challenges aside，as we continue to expand our exploration of Mars，there is a question：What might be the lessons of past voyages of discovery that we should think about?
Human exploration has led to many extraordinary new discoveries，but it has also led to the exploitation (开发) of resources. Not long after early European settlers arrived in America，they declared their independence and created the constitution by which modern American society functions. However, this did not prevent the settlers from referring to native people as savages and taking away their rights to liberty，happiness，and even survival. Native Americans were quickly killed by wars and new diseases as the new settlers expanded their land. The natural environment，with which they had established a harmonious relationship，was similarly destroyed by the settlement.
Mars certainly has an impossible environment for human life，but on Mars，humans will be the invasive (侵略的) species. Will our landing on Mars break the ecosystem on Mars？It is possible that Mars has ideal minerals for future development. But apart from technology challenges，will the mining have a disastrous environment impact on this red neighbour as it has already had on Earth?
The achievements of space exploration are certainly to be applauded. The contributions of the related research on chemistry，medicine and many others are potentially limitless. However，as we look to exploring worlds beyond our own，we need to begin now to look at history to consider how best to engage with different life forms，cultures and environments. We may be capable of writing a law，but we first need to clear our potential invasive impact on another planet that may be completely defenseless.
