Four and a half billion years ago, somewhere not far from a young, medium-sized yellow starThe colour of a star depends on how hot it is. The very hottest stars, at 30,000 degrees celsius or above, are blue, while the coolest, at less than 3,300 degrees, are red. Our sun, at 6,000 degrees, is on the cooler side., two small planets collided. The impact vaporised the upper crust of one planet and smashed the other into smithereens.

The debris from this collision was dragged into orbit and mercilessly pulverised into a smooth sphere: the moon. Back on Earth, meanwhile, something unusual was happening. The hot rocks thrown up by the collision created an atmosphere mostly of carbon dioxide and water vapour. And from this water, oceans began to form.

Millions of years later, tiny organisms began to make their way around these vast seas. Although the moon had been instrumental in life's formation, it would be almost four billion years before any animal would look up from the Earth and see its white light shining in the sky.

Now, new evidence suggests that the moon has its own reserves of water, not the vast oceans that we find on Earth - but tiny molecules trapped in lunar dustA fine dust on the surface of the moon, formed by the debris from asteroid collisions. Because it is quite abrasive, Nasa is concerned that it could damage equipment and harm astronauts who spend prolonged periods on the moon.. Nasa hopes to use these reserves to construct a base on the moon.

The lunar water could be put to all sorts of uses: its component elements - oxygenAn element that is vital for life on Earth. It makes up 21% of our atmosphere. and hydrogen - can be used as fuel in liquid form. It could also be used to supply vital oxygen to astronauts.

Because the atmosphereThe layer of gases surrounding a planet or moon, held in place by that planet's gravity. Small planets and moons have weak gravitational fields, and therefore only a very thin atmosphere. of the moon is much thinner than that of Earth, it is easier to launch rockets there. Nasa could therefore use a lunar base to send missions deep into space. In short, water on the moon could be the key to landing an astronaut on Mars.

However, the discovery of water on the moon has also sparked new conflict over the exploitation of its resources.

On 14 October, eight nations, including the USA, UK, and Japan, signed the Artemis Accords, a new treaty designed to regulate safety, co-operation, the operation of space hardware, sustainable use of resources, and the disposal of space debris in future missions.

The accords are designed to support Nasa's Artemis programme, which aims to land astronauts on the moon by 2024. Among them will be the first woman ever to set foot on the lunar surface. It also hopes to establish a lunar base, with a permanent crew, by 2030.

Some countries have refused to sign the accords, accusing the USA of trying to seize lunar resources for itself. The accords explicitly state that mining on the moon is permissible under international law. This follows the Space Act of 2015, which enshrined the right to use and trade space resources in US domestic law.

The head of Russia's space agency, Dmitry Rogozin, claims that the accords are "too US-centric" and should be based on "principles of international co-operation". China has also avoided involvement in the programme.

But it is not just the USA's enemies and rivals that have refused to sign the Artemis Accords. France, Germany, and India are absent from the signatories, suggesting that these countries, with their own well-developed space programmes, are unwilling to ratify a treaty that risks handing the USA a headstart in lunar exploitation.

Yes, say some. They claim that competition for ownership of the moon might force countries to innovate new space travel technologies. In the 1950s and 1960s, the Space Race between the USA and the USSR drove each country to invest in their space programmes. The result was that within just 12 years, humanity went from sending its first satellite into space, to putting a man on the moon.

No, say others. They point to the example of AntarcticaThe most southerly continent, surrounding the South Pole. Its area is estimated at 5.5 million square miles, most of it covered in ice.: initially, various countries laid claim to Antarctica, and almost went to war over it. However, the 1961 Antarctic Treaty cancelled all of these claims, and now scientists of all nations collaborate on Antarctic research. International co-operation in moon exploration is necessary to avoid conflict between countries on Earth.