Back in the 1960s, the race for the moon was the central technological battleground. But after the demise of the Apollo program in 1972, the world largely forgot about our satellite. Russia sent a sample return mission in 1976, but after that, the next controlled landing was China’s Chang’e 3 lunar rover mission in 2013.

But interest in the lunar landscape is once again heating up. If all goes to plan, six spacecraft will touch down on the lunar surface by 2020, equipped with landers, samplers, and return capsules.

One of these is a private mission funded by the U.S. robotics company Astrobotics Technology. Its goal is to win the $20 million Google Lunar X Prize for the first privately funded robotic spacecraft to land on the surface.

The moon is becoming a veritable tourist hotspot.

And that raises an interesting set of questions about legal rights to the lunar surface; essentially, who is going to own or control it?

At first glance, this question is easily answered. Lunar property ownership is forbidden by an international agreement called the Outer Space Treaty that came into force in 1967. The Treaty stipulates that the moon is the province of all humankind.

But there are some significant loopholes in this Treaty, say Martin Elvis at the Harvard-Smithsonian Center for Astrophysics in Cambridge and a couple of pals. And these loopholes are likely to lead to certain forms of property claim in the coming years as the next lunar space race hots up.

Elvis and co begin by pointing out that the Outer Space Treaty assumes the lunar surface to be more or less uniform so that the occupation of one region will not deprive others of important lunar resources.

But the recent high-resolution mapping of the lunar surface has begun to challenge this assumption. Some tiny parts of the moon are vastly more valuable than others, and it is these places that are likely to be occupied first.

Elvis and co have devised a thought experiment to explore the issues likely to arise when competition emerges for the moon’s most valuable real estate. This thought experiment focuses on a small number of sites at the north and south poles of the moon, which are in almost permanent sunlight—the so-called Peaks of Eternal Light.

These places are valuable because any lander has access to continuous solar power and so requires fewer batteries to survive the lunar night. The temperature will also be more constant, requiring less thermal management, and so spacecraft design can be simpler too.

The Peaks of Eternal Light are tiny. In general they occur along the rims of craters and so tend to be a long and thin. Known peaks are just a few meters wide and perhaps a hundred meters long, like a strip at the edge of a football field.

Another valuable resource on the moon is water ice, which is thought to exist in some craters near the South Pole which are in permanent darkness. The ice here is likely to be leftover cometary debris which has never melted away.

The dream scenario is to find a Peak of Eternal Light close to a Crater of Everlasting Darkness. In that case, a lunar mission based on this spot has access to continuous cheap power to mine the water there. Such a location is likely to be hugely valuable and highly sought after because it allows the industrial development of the moon. “This combination is also extremely rare on the moon and it is the power supply that is scarcest of the pair,” say Elvis and co.

The team analyzes the surface looking for these valuable spots. “In the case of the Peaks of Eternal Light, the resource in question is so scarce that even a single country or company could, on its own, occupy them all, effectively denying that resource to others,” point out Elvis and co.

So simply occupying a peak denies anyone else access because it is so small.

And the probability of this causing a dispute is high. “As always when resources are concentrated, this clustered distribution of high illumination regions will eventually lead to disputes over rights to those resources,” say Elvis and co. “The first case of trusted identification might trigger a ‘scramble for the moon’ comparable in some respects to the ‘scramble for Africa’ which began with the identification of mineral resources in the Congo in the 1880s.”

This scenario is more likely than it might first seem, not least because the area in question occupies just a trillionth of the total lunar surface.

In their thought experiment, Elvis and co consider the case of a radio telescope based on a Peak of Eternal Light. Such a telescope is an attractive prospect because it could explore the last part of the electromagnetic spectrum that is inaccessible from Earth, which consists of waves longer than 10 meters or so and a frequency lower than 30 MHz.

Such a telescope would be simple to construct. Its antenna would be a long uncovered wire at least 100 meters long. “It would naturally run the length of one of the long, thin, Peaks of Eternal Light,” say Elvis and co.

This would be simple and cheap to unspool and eminently achievable with today’s technology. And when built, it could unblinkingly observe the heavens, the sun in particular, powered continuously by sunlight. This observatory would be unique and of significant scientific value.

But here’s the thing. Such a telescope would be hugely sensitive to electrical interference and the posts that support it would be vulnerable to vibration. So the area around the telescope would have to be out of bounds to other landers, this area might include a Crater of Everlasting Darkness with valuable water resources.

In other words, the very act of setting up such a telescope co-opts this valuable land and anything around it. “Effectively a single wire could co-opt one of the most valuable pieces of territory on the moon into something approaching real estate,” say Elvis and co.

It doesn’t take much imagination to think of various scenarios in which international tensions rise along with political blood pressures.

Elvis and go on to argue that the world needs to get to grips with this issue now to develop some kind of workable policy. The alternative is being shocked into action by a fait accompli of some kind.

It’s clear which of these options is preferable. It’s less clear which will come to pass. If a scramble for the moon occurs, it could involve countries, private companies, and perhaps entire continents in a  new space race that will have unpredictable outcomes.

Ref: arxiv.org/abs/1608.01989: The Peaks of Eternal Light: A Near-term Property Issue on the Moon