Who owns the moon? What about Mars?

For now, the answer is no one, but as more private companies, billionaire entrepreneurs and national governments start casting their eyes on space, the question could change from a futuristic problem into a real issue.

Under the 1967 Outer Space Treaty, which governs international space law, no one nation can claim sovereignty over a body in space. But there could be a loophole.

Full blown colonization and settlement of other planets, moons and even asteroids might actually happen, says space policy consultant Rand Simberg, if a government could provide one thing: property rights.

Parceling out plots of land on celestial bodies might encourage people to invest in these properties, and this would benefit Earth economically, according to Simberg. He proposes the Space Settlement Prize Act and lays out how such a scheme would work in a new paper published by the Competitive Enterprise Institute, a libertarian think tank, on Apr. 2.

The international community might never buy into such a plan. The Outer Space Treaty states that space is the "common interest of all mankind" and that exploration or use of it "should be carried on for the benefit of all peoples." Traditionally, this has been interpreted as prohibiting private property claims on other bodies in the solar system. The U.S., along with dozens of other countries, has ratified the treaty.

Handing out property rights to individuals and private companies would be a major shift from current thinking about outer space.

But Simberg argues that the treaty doesn't explicitly prevent private companies from claiming territory. Though, if the U.S. government accepted such a claim, that could be taken as a declaration of sovereignty, which might violate the Outer Space Treaty, said space law attorney Michael Listner.

"It's a very touchy issue," Listner added. The U.S. could possibly withdraw from the Outer Space Treaty but "to take that stand against the rest of the world, would take a lot of political will and the government would take a hit. It's sort of a nonstarter."

Of course, Simberg's model does have historical analogues.

"It's similar to the way properties were pioneered in the Old West," said Listner. "The government opened up land and people went to settle it."

Claiming land on the moon would certainly violate the 1979 Moon Treaty, which specifically bans any nation from asserting sovereignty over any part of the moon and prohibits ownership by private persons. But the major spacefaring nations – including the U.S., Russia, and China – have never ratified this international treaty and it is often considered dead legislation.

An Earth-based analogue to the Moon Treaty is the 1961 Antarctic Treaty, which states that the continent should be open to all nations for scientific and peaceful purposes. But many countries would love to find a way to grab Antarctic land in hopes of extracting rich mineral deposits and other resources.

The main obstacle to enacting a law like the Space Settlement Prize Act is political. Congress is not thinking much about extraterrestrial property rights and is instead currently focused on budget cuts and finding the best course for the U.S. space program.

But Simberg's paper suggests the time is ripe. It cites Moon Express, Inc. and the Shackleton Energy Company as two corporations with plans to extract lunar resources for further space exploration.

"The sooner we put policy in place and encourage this, the sooner it will happen," Simberg said.

Others say that the issue is not yet pressing. Most private spaceflight companies are only thinking about sending people and supplies to low-Earth orbit, with flights to the moon or Mars many years off. "These topics are simmering right now, but they haven't come to a boil," said Listner.

What about the environmental toll of mining and drilling on the moon? The Moon Treaty states that explorers should try to prevent disrupting the existing lunar environment as much as possible.

But Simberg doesn't see this as a pressing matter. "There are people who believe that rocks have rights; I'm not one of them," he said.

Image: NASA/Pat Rawlings