Assuming more than one country is involved with the mission that first lands on Mars, then how will the ownership of land be decided? Would Mars territory be treated as land in Antarctica in that it cannot be owned but merely maintained. What happens if a country capable of travel to Mars that also happens to have been denied membership into the ISS community decides to travel to Mars and claim plots of land as their own? Could we rightfully deny them their right to exploration simply because we don't trust their current motives? After all, if no one owns Mars then how could any one country dictate who has the right to claim ownership of a planet other than our own? Would embassies be necessary in such an environment?