If there is one thing we can rely on in this world, it is human hubris, and space and astronomy are no exception.

The ancients believed that everything revolved around Earth. In the 16th century, Copernicus and his peers overturned that view with the heliocentric model. Since then, telescopes and spacecraft have revealed just how insignificant we are. There are hundreds of billions of stars in our galaxy, the Milky Way, each star a sun like ours, many with planets orbiting them. In 1995, the Hubble space telescope captured its first deep-field image: this showed us that there are hundreds of billions of galaxies in our known universe, huge wheeling collections of stars dispersed through space.

Let’s take the International Astronomical Union’s definition of space as everything in the universe apart from our planet and atmosphere. Asking the question “who owns space?” seems laughable. Hubris at a whole new level. The idea that we could lay claim to the rest of the universe is beyond conceit. It’s like a group of atoms in my little toe becoming sentient and declaring that they now own my whole body.

A few years ago, I postulated that space exploration could be divided into three distinct eras. The first was confrontation. It was the second world war that fuelled our first forays into the abyss, as this proved to be an effective way of lobbing munitions further. The space race was born from military competition – in a bid to establish superiority. The second era brought collaboration. The formation of the European Space Agency in 1975 and that symbolic docking between Soviet and American space vehicles symbolised what humanity could achieve collectively. But now we’re on the verge of a third era: commercialisation. Space exploration is no longer just the domain of nations, but of billionaires, private companies and start-ups promising holidays in orbit.

Of course, the space industry has been commercial for decades – many communications satellites, Earth-observation systems and some launch vehicles are privately funded and operated. But what’s changing is that humans themselves are now part of the business plan, as we move from exploration to possible exploitation. Private space stations, space tourism, lunar and asteroid mining – this is the new frontier. So the question of ownership suddenly has legal, ethical and economic urgency.

Legally speaking, the groundwork for managing space was laid long ago. In the late 1950s and early 60s, as rockets first breached Earth’s atmosphere, the United Nations drafted agreements to govern activities beyond our planet. The Outer Space Treaty of 1967 set out some remarkably idealistic principles: “The exploration and use of outer space, including the moon and other celestial bodies, shall be carried out for the benefit and in the interests of all countries, irrespective of their degree of economic or scientific development, and shall be the province of all mankind.” I would reword it to humankind, but I do like the sentiment.

It’s a beautiful vision, but potentially an increasingly fragile one. As technology advances, these noble principles will come face to face with economic reality. When a commercial company finds a valuable mineral deposit on the moon or an asteroid, who gets to profit?

I would argue that commercialisation is necessary – space needs to pay for itself, because without profit, humanity will stay “terra-bound” for centuries. Exploration is expensive, and governments alone can’t afford to foot the bill. If mining helium-3 or capturing asteroids helps fund missions that expand our knowledge, capabilities and improve our husbandry of our planet, that could be a good thing. But commercialisation must come with equity and transparency. Otherwise, we risk repeating the mistakes of our past, but on a truly cosmic scale.

The comparison I often like to make is with the East India Company: a private British enterprise that became so powerful it could shape the politics of nations and at times had an army twice the size of Britain’s. It began as trade; it ended in domination. Could a similar dynamic unfold locally in our solar system, where a handful of today’s tech giants and billionaires control access to orbit, communications, and eventually, extraterrestrial resources? A monopoly in space would be dangerous for humanity. The challenge is to encourage innovation and investment without ceding ownership of the cosmos to a few individuals or organisations.

The moon is a fascinating case study. For scientists, it serves as a natural laboratory – a place to study planetary history and test new technologies. But it’s also an appealing commercial target. There’s water ice at its poles, which can be split into hydrogen and oxygen to make rocket fuel. Its gravity is only one-sixth of Earth’s, making it a sound launch base for deeper space exploration. And some have suggested mining the lunar surface for helium-3, a potential fuel for future fusion reactors. The possibilities are tantalising. But who decides how the moon’s resources should be used, and by whom?

The Outer Space Treaty forbids national appropriation, but it doesn’t explicitly prohibit private companies from extracting resources. That ambiguity has prompted countries such as the United States and Luxembourg to pass their own space-mining laws, granting rights to their domestic firms. Yet if each nation makes its own rules, could the result be chaos like the early wild west – or even conflict? Space, by its nature, demands global regulation.

That’s why I believe we need to revive the spirit of the early treaties, not just in words but through action. Space should be regarded as a shared domain, similar to the high seas or, perhaps more fittingly, Antarctica. No one owns Antarctica. It is protected for peaceful research under an international agreement. That hasn’t stopped some countries from eyeing its minerals, but the principle remains: collective stewardship. Space warrants the same approach. The way we behave in the third era of space will define not just the future of exploration, but the kind of species we are. Do we carry our old rivalries and greed into the stars, or do we finally learn to act as one planet, united by curiosity and care?

As always, I’m hopeful. I trust the new generation to do a better job, and space has a way of putting things into perspective. When astronauts look down at Earth from orbit, they describe a sense of awe, known as the “overview effect”. They see our planet as it really is, fragile and shared. Perhaps if we can hold on to that view, even as we venture further out, we might be able to reach for the stars in a way that benefits everyone.

• Dame Dr Maggie Aderin-Pocock will deliver the 2025 Christmas Lectures from the Royal Institution.

Further reading

Orbital by Samantha Harvey (Jonathan Cape, £9.99)

Who Owns the Moon? by AC Grayling (Oneworld, £10.99)

A City on Mars by Dr Kelly Weinersmith and Zach Weinersmith (Penguin, £11.69)