What if we mined the Moon?

Thanks to our exploration of the Moon over the past decades, we now know that it is a potentially huge repository of natural wealth. For a start, there appears to be abundant water ice at the Moon’s south pole – crucial for setting up lunar bases or colonies.

There are rare-earth metals such as neodymium and lanthanum, which are used in technologies like speakers, smartphones, batteries and camera lenses, and there are plenty of other useful metals, such as silicon, titanium and aluminium.

What’s more, it’s thought that the Moon’s surface has a relatively high concentration of a rare isotope of helium called ‘helium-3’, which could be used to power future nuclear fusion reactors. Companies are already drawing up plans to develop the technology to mine the Moon. But what would be the consequences of going after these resources? A Moon race is hotting up again. This time, it’s not just between the US and the USSR, as it was in the 1960s. Instead, many countries, such as India and China, are involved, as well as private companies such as SpaceX in America and SpaceIL in Israel.

They are interested in finding a way to build a presence on the Moon that will be sustainable over the long-term. And they are also interested in whether mining the Moon can be a feasible economic prospect. Strikingly, there is little international law to regulate this endeavour.

The so-called Moon Treaty was opened for countries to sign in 1979. It tried to protect the Moon by calling for it to become the ‘common heritage of mankind’. But although the treaty became active in 1984, no major space-faring power has ever signed it – the US, UK, Russia, China and Japan are all notable by their absences.

This lack of take-up is largely because ‘common heritage’ implies shared ownership and the equitable distribution of resources. So, the proceeds from the sale of any resources mined on the Moon would have to be equally distributed around the Earth, rather than kept by the country or company that extracted them. And very few countries, it seems, are willing to sign away their profits for the common good.

What’s unfortunate is that the treaty also called for an international body to govern the exploitation of the Moon’s natural resources. Without such regulation, a winner-takes-all mentality could take hold, leading to a kind of lunar ‘gold rush’ by the countries and companies that can afford to make the trip.

All you need to manufacture rocket fuel is water. A process called ‘electrolysis’ splits water into hydrogen and oxygen, which can together be used as fuel. And if we are going to attempt a mission to Mars, then we’re going to need a lot of fuel.

Manufacturing the fuel on Earth may seem like the obvious answer, but it then needs to be launched into space. To overcome our planet’s massive gravitational field, rockets must reach speeds of 11km/s, and that takes a lot of money. The Moon, though, has only one-sixth the gravity of the Earth, and so fuel could be launched a lot more cheaply once it has been made.

The Moon is a scientific time capsule. As it lacks an atmosphere, there is no weathering or erosion of its surface. The cratered face we see represents 4.5 billion years of astronomical history. We’ve lost that ancient geological record on Earth because of erosion and the endless recycling of the planet’s crust via plate tectonics. Could mining cause the Moon to go in the same direction?

Even before we get to the mining stage, the mere act of setting up a lunar base for mining operations will involve destroying large quantities of the lunar soil (‘regolith’) to make way for buildings, or to make the building material itself. Any of the destroyed rocks could contain valuable geological clues as to how the Moon, and by extension the Earth, formed.

Science Focus