Will there ever be colonies of human beings who live, work and raise families on extra-terrestrial soil? The prospect is certainly a tantalising one and some are so enamoured of the idea of extra-terrestrial colonisation that they see it as essential for our long-term survival in the universe.
Professor Stephen Hawking is one such individual. Given the potential for impending doom awaiting planet Earth on a daily basis in the form of climate change and nuclear holocaust, he believes it imperative that we up sticks, suggesting “our only chance of long-term survival is not to remain lurking on planet Earth, but to spread out into space.”
He has a fair point, in the long-term at least. While the Earth is unlikely to ever get so overpopulated that some of us would have to leave (most biologists believe that the Earth’s human ‘carrying capacity’ is not necessarily a fixed element), the planet won’t be around forever. The Sun is nearing its 40th birthday as far as stellar life cycles are concerned and is set to burn out within a few billion years, and with it goes the planet.
That may sound like a long way off, but eventually the day will come and the human race, assuming it’s still around, will have to leave this solar system and find a new planet to live on. Given that the traversal of interstellar distances takes quite a long time, extra-terrestrial colonisation before then will be crucial in facilitating humanity’s gradual expansion out across the stars, by setting up waypoints between Earth and any final destination.
Taking Professor Hawking more literally in his assertions, many believe that the colonisation of other planets would be just as difficult as attempting to overcome any apocalyptic scenarios the Earth might face in the near future, and that by focussing on extra-terrestrial exploration we are detracting from real efforts to solve genuinely preventable problems such as climate change. That said, most would agree that it’s probably better not to put all our eggs in one basket, and it might be nice to have a back up colony of humans somewhere else in the galaxy just in case the Earth gets hit by an asteroid tomorrow.
There are other valid reasons to colonise other planets too, chief among these being the simple human desire to explore new worlds and new civilisations, there’s no reason the history book should stop with Magellan et al.
However, astronomer and futurist Martin Rees has long pointed out that “there is nowhere we know about in our own Solar System that is even as hospitable as the top of Everest or the South Pole.” In other words: even if we wanted to settle on a new planet, we’d still have to make it liveable first.
There are a number of options available. The first of which is the type of set-up we see in nuclear submarines and the international space station, where the colonists live within a totally enclosed habitat which supplies them with all the necessities of life and protects them from the harsh external alien environment.
Such a system could be as simple or as sophisticated as desired, with researchers at the Biosphere 2 project in Arizona looking into the viability of a fully functioning self-contained ecosystem which would automatically provide most of the needs of its human occupants, such as food and oxygen. This approach has some obvious drawbacks such as its vulnerability if anything went wrong and the inevitable reliance on external resources such as raw materials and medicines, depending on the complexity of the set-up.
Terraforming may be a preferable, albeit more expensive, alternative. Futurist Michio Kaku explains how the best approach would be to take full advantage of the resources the elected planet has to offer. Using Mars as an example, Kaku proposes heating up the planet somehow, perhaps using hydrogen bombs. This would set off a chain reaction, causing water ice beneath the planet’s surface to melt and release carbon dioxide. This liberated gas could go on to produce a rudimentary atmosphere and trap in some heat from the sun via the greenhouse effect. This would heat the planet further, melting deeper deposits of ice and freeing more carbon dioxide until the temperature is raised enough for specially-modified forms of plant life to be introduced, which would produce oxygen via photosynthesis and eventually create an environment similar to our own.
While terraforming is wrought with all kinds of engineering kinks and would take a long time to realise, it probably represents our best means of truly colonising another world. However, even given adequate basic environmental conditions, everything may not be rosy: the colonised planet may still have a very thin atmosphere which would expose colonists to high levels of deadly cosmic radiation, or it may have very high or very low gravity causing circulatory problems and muscle wasting. As such, many posit that a heady mix of genetic engineering and cybernetic enhancement must be employed alongside other efforts, to ensure that prospective colonists will survive and be able to live normally on their new home.
While the idea of living on another planet is hugely compelling, attention in space exploration is currently more focussed on advances in robotic technology which would allow us to ‘go there’ without actually having to go there, meaning extra-terrestrial living probably won’t become a reality for some time.
Still, a variety of (largely private) interest groups around the world are pushing forward regardless. With the likes of the Artemis Project planning to put a human colony on the moon in the near future, we might be breaking out our zero-gravity pouches of synthahol sooner than we think.