What about life on Mars? Or any other planet?

Other experts favour the idea of setting up home on firmer ground – a planet or moon – creating an artificial “biosphere” with all the necessary elements for human life to thrive. Mars has become a main focus of attention, and astonishingly, people are already trying to make steps to set-up a new civilisation there by 2025. The Dutch project, called Mars One, was launched in 2012 and it has already vetted 40 applicants from a pool of 200,000. They should now receive training as part of a reality TV show that is helping to fund the project. Needless to say, Mars One has its detractors – but it does at least show the vast interest in colonising space.

SpaceX’s Musk is also rumoured to have his sights set on populating the Red Planet with a colossal vehicle called the Mars Colonial Transporter, which if it were reusable could cut the costs of return trips. As he told Aeon recently, that would only be the beginning: “If we can establish a Mars colony, we can almost certainly colonise the whole Solar System, because we’ll have created a strong economic forcing function for the improvement of space travel. We’ll go to the moons of Jupiter, at least some of the outer ones for sure, and probably Titan on Saturn, and the asteroids.” Even Musk draws the line at inhabiting other stars, however. “Alpha Centauri is four light years away, so if you go at 10% of the speed of light, it’s going to take you 40 years, and that’s assuming you can instantly reach that speed, which isn’t going to be the case… I just wonder what humanity will even look like when we try to do that.”

OK, forget the stars. But how would we cope with life in space? Or getting there?

Life on the International Space Station reveals some of the massive challenges we would face. Simply ferrying enough water for its six inhabitants costs around $2 billion per year. That’s not to mention the difficulties of providing food and oxygen. Ideally, a space colony would need to become self-sufficient, generating all these resources itself or perhaps mining them from nearby asteroids.

Then there are the stresses to the human body: reduced gravity can lead to bone and muscle loss and a dangerous build-up of pressure in the head, which can sometimes lead to temporary and persistent eye problems. Cosmic radiation, meanwhile, can cause cataracts and increase the risk of cancer. Sleep loss and loneliness, meanwhile, could wreak havoc on the mind. Any space colony would need to solve all these difficulties, and more – including surprising day-to-day practical issues, such as the fact that some materials – including human facial hair – tend to be more flammable in lower gravity.