Earlier this year, Stephen Hawking said in a speech that in order for humanity to survive, we must begin colonizing other planets within the next thousand to 10 thousand years. He made a good argument for the necessity of such an action, as have other scientists for the last several decades. For years, NASA scientists have been arguing that unless humans establish human habitation on other planets, we may face extinction. While we're still on a single planet, our position is rather delicate- any significant natural or man-made disaster could destroy all of us. A thermonuclear war could wipe out every human being on this planet, as could a powerful enough volcanic explosion, or unchecked climate change (either human caused or natural). A nearby star could go supernova and bathe our tiny blue planet in enormous energies, boiling the hemisphere facing the star, and irradiating the other. One stray asteroid is all it would take for us to go the way of the dinosaurs.
The only way to avoid this, to escape our delicate and dangerous situation, is to have human habitations on a multitude of planets, in a multitude of star systems. If we have colonies across the galaxy, the loss of our home planet will still be a tragedy- but it won't be the end of our species.
It's not just absolute extinction that threatens us, but a limited number of resources. The planet is already overpopulated by humans, and is buckling under our weight. As a whole, we are already using one and a half times as many resources every year than the planet can replenish in that year- and that's just the renewable resources. We're also running low on habitable land space, and are already doing enormous damage to the environment by pushing deeper and deeper into previously untouched and untamed territory. In our endless hunt for more space, more food, more resources, we are damaging our planet, and ourselves.
But space colonization provides the answer yet again. By colonizing otherwise empty planets, we aren't damaging any existing ecosystem- we're creating them. We're tapping into the vast, nearly unlimited resources of the galaxy. If we can just overcome the initial problems, those first hurdles on the road to space colonization, we'll be set. We'll never run out of living space, we'll never run out of metals, we'll never run out of solar energy.
At the moment, we've yet to even meaningfully attempt those initial hurdles. We need to find a way to feed human colonists on empty planets, to sustain survivable habitation in the vacuum of space, to travel at reasonable speeds to other star systems in a way that won't take up entire generations.
However, scientists are already thinking ahead, and cataloging dozens, hundreds of exoplanets- planets orbiting stars other than our own- and have already found thirty potential candidates for human colonization. Only in these last few months, scientists at MIT have discovered three more planets orbiting their sun at just the right distance to sustain survivable temperatures and liquid water, only 40 light-years away from our own system.
Perhaps, in our lifetime, we'll be lucky enough to witness and even experience the first steps of space colonization. Perhaps some of us, or our children, will be the first humans to live permanently on Mars, or the moons of Jupiter. Maybe our children's children will tiptoe out of the shallows of our own solar system, into the depths of the greater galaxy. Maybe we'll be alive to see them send humans to the nearest star systems, with the hope of planting colonies on even more distant and alien worlds.
Or maybe we'll kill ourselves in thermonuclear war before we even get the chance. Only time will tell.
