If a country – Russia, say – managed to send cosmonauts to Mars, would they be able to claim the planet for Russia?

If a country – Russia, say – managed to send cosmonauts to Mars, would they be able to claim the planet for Russia?
Pioneer … artist’s impression of the European Space Agency’s ExoMars probe mission orbiting Mars.
Photograph: ESA/PA

Can the first nation to Mars claim the planet for itself? If a country – Russia, say – managed to send cosmonauts to Mars, would they be able to claim the planet for Russia? Are there rules governing territorial claims in space? originally published on The Guardian, (The long-running series in which readers answer other readers’ questions on subjects ranging from trivial flights of fancy to profound scientific concepts.)

While it is true that the Outer Space Treaty does mention that no nation can claim a planetary body and it does not mention anything about individuals claiming planetary bodies. This aside, there is a common law doctrine that could come into play in Elon’s favor about his ownership of Mars.

By Russell Newman , worked at SpaceX / originally published on Quora.com

While it is true that the Outer Space Treaty does mention that no nation can claim a planetary body and it does not mention anything about individuals claiming planetary bodies. This aside, there is a common law doctrine that could come into play in Elon’s favor about his ownership of Mars.

Doctrine of First Possession

This basically says that if you are the first to possess (special legal definition) something then you are the now the owner of it. For you to claim possession you must have both control and intention and possession goes into effect as soon as those two conditions are meet [1]. This is not the same as adverse possession which gives new ownership to a previously owned object. This is for items that have not had ownership assigned before, i.e Mars.

For Elon to ‘own’ Mars he must intend to possess Mars and he must ‘control’ Mars. In our scenario he already has the intention to claim Mars so this condition is satisfied. The crux lies in how do you ‘control’ Mars.

Just owning the means to get to Mars would not be strong enough. The rockets don’t count. I’ll willing to bet that there is legal precedence that you can’t just build a road up to a harbor and claim you control, and therefore, own the whole harbor. You need to show a physical or potential physical control of the entire area to ‘control’ it. You also can’t own the orbit of Mars because space is not property.

Landing on Mars in of itself would also not be strong enough to own all of Mars. Elon would own his landing site and the all the area a reasonable distance from his landing site but not all of Mars from just landing on it first. My guess is that you would own up to the visible horizon of any structure you build (on Mars the horizon is 3.40 km away [2]).

Another way he could claim land on Mars is by building a fence around the land he intends to own. This is not likely to happen as it is probably going to be very expensive to build millions of miles of fences with the first colonists to Mars. (also how do you build a fence to enclose all the area of a sphere?)

The best way to claim land on Mars is by building something. The simplest thing you can build would be roads. If you build a road you could claim +/- 3.4 km to each side of your road as your property. You can claim wide swatches of land by building lots and roads. Now the question is what qualifies as a “road”. The answer would be “suitable for the purpose of a road which is to provide easy travel and navigation”. So you can build roads on Mars by clearing all rocks out of the way and demarcating clearly what is the road and what is the wilderness.

My Prediction

Elon would have a 20-30 year head start before other competitors start to also land people on Mars. During this time Elon and the first colonists would be able to nab a lot of the cool landing spots, build some pretty sizable cities, and build a tons and tons of simple roads. His people would own 1,000’s of square km but not all of Mars.

Mars is 140 million square km. This means that there is plenty of space for everybody. We should not have any real estate conflicts with the Russians or the Chinese for at least a couple centuries.