Can People Stake Claims on Mars?*
*In collaboration and written jointly with Sean McCormick
Earlier this month, Elon Musk addressed the International Space Station Research and Development Conference. His address was wide ranging, covering SpaceX’s plans for the Falcon Heavy and a permanent settlement on Mars.
Speaking candidly, Musk addressed many of the challenges and risks that a Mars settlement would pose. During this Q&A, one poignant question raised our legal eyebrows: how would people deal with conflicts over land and terrestrial space on Mars? But Musk brushed the question off, responding that the planet is big enough for everyone to share.
Musk can be forgiven for not spending much time on this issue—his mind was probably preoccupied with both the Tesla Model 3 and the Falcon Heavy launch. But if SpaceX or another entity successfully transports people to Mars, won’t the growing human population there lead to interpersonal conflicts over land? Is it even possible for people or companies to stake claims and hold private property on Mars? Does the international community have the right tools to properly regulate such activities?
For this quest, we need to dive into the fabrics of space law, a brand of international law; space law is unique in that its sources are international treaties and longstanding, unwritten principles that the international community respects. On the topic of Martian colonies, two treaties provide guidance: the Outer Space Treaty of 1967 and the Moon Treaty of 1979.
Outer Space Treaty of 1967
The Outer Space Treaty of 1967 is arguably the broadest, most respected authority regarding space law. It has been ratified by more than 100 nations, and it contains fundamental legal concepts about space and celestial bodies that have become widely accepted.
Two principles from the Outer Space Treaty are relevant here. First, as stated by Article II, nations may not lay sovereign claims, “by means of use or occupation, or by any other means,” to any part of Mars, or any other celestial body. Hence, the United States, or any other nation, is prohibited from staking a claim to Mars or extending its sovereignty to any part of Mars. But SpaceX isn’t the United States government. SpaceX is a private company ostensibly acting in its own interests, not the government’s.
One might argue that SpaceX is an extension of the American government. After all, SpaceX will undoubtedly receive large amounts of funds from the government to go to Mars. But, putting that argument aside, does the Outer Space Treaty’s rule prohibiting the extension of sovereignty apply to private companies?
That brings us to the second relevant principle under the Outer Space Treaty. Under Article VI of the treaty, nations bear responsibility for regulating and overseeing their national activities in space. This includes activities by both governmental and non-governmental organizations. Thus, the United States is required to regulate and supervise SpaceX’s activities in space and on Mars. Additionally, per Article VII, the United States will be “internationally liable for damage[s]” caused by SpaceX. Using this principle, the international community might reasonably pressure the United States to prohibit private American companies from staking private claims.
Moon Treaty of 1979
The Moon Treaty also sought to address concerns about non-governmental organizations staking claims to private property on the Moon and other celestial bodies. It states, in Article 11, that the surface of the Moon, and other planets and celestial bodies, cannot become property of any state, non-governmental organization, or natural person.
Unfortunately, the Moon Treaty has not enjoyed widespread adoption in the international community. Only 17 nations have ratified it. The most advanced spacefaring nations—the United States, Russia, China, Japan, India, and many members of the European Space Agency—failed to ratify it. So the Moon Treaty carries little weight in international law.
In any event, even though the Moon Treaty does not permit entities to claim private properties rights over celestial bodies, it does not prohibit them from placing personnel, equipment, structures, or facilities on celestial bodies. Presumably, entities that are permitted to construct facilities are permitted to protect and defend those facilities.
So while there is no clear authority prohibiting a company like SpaceX from staking claim to Martian property, the international community has tools, such as the Outer Space Treaty, to push back. For instance, international pressure might cause the United States to prohibit its own companies from claiming property rights on Mars.
A Foreign Environment
But, the story doesn’t end here. Our concepts of private property may be impractical on Mars, at least initially. That is because early settlers will not be able to freely explore, claim, and live off of the land the way they did on Earth. Before we terraform Mars, the low-pressure Martian atmosphere will restrict settlers to their space suits and habitats. Thus, during the early stages, ownership of Martian habitats will matter as much ownership of land.
Here, again, the Outer Space Treaty is relevant. Article VIII notes that the nation “whose registry an object launched into outer space is carried shall retain jurisdiction and control over such object, and any personnel thereof, while in outer space or on a celestial body.” The treaty further notes that this ownership status isn’t altered by the fact that such objects are “landed or constructed on a celestial body.”
While SpaceX might not be able to claim property rights on Mars, it (and the United States) will own and control the physical infrastructure of a colony, where all settlers must live. These colonies, however, must remain “open” to all nations. The Outer Space Treaty states, in Article XII, that all “stations, installations, [and] equipment” on celestial bodies shall be open to representatives of all nations that are bound by the treaty “on the basis of reciprocity.” Hence, even if SpaceX/United States owns and controls a colony on Mars, all Martian colonists should be able to enjoy freedom of access to such colony. Until these colonies are built, however, it remains to be seen whether colonists will indeed enjoy such access.