Last Friday, our planet just barely dodged a very large, fast moving space-rock. As it approached, a smaller asteroid struck Russia, exploding in a fireball which reportedly injured over a thousand people, evoking memories of the great Tunguska explosion a century ago in Siberia. News like this demonstrates that while the risk of an asteroid strike is remote, it’s not impossible.

Given the velocities involved, it doesn’t take a very large rock to threaten a large part of life on earth. Even small asteroids can build up enough heat to go off like a nuclear bmob the Tunguska Event is estimated at around 10-15 megatons, making it around a thousand times the power of the atom bomb dropped on Hiroshima. A larger rock could hit the ground, triggering an effect more like a super-volcano and cover the globe with a dust-cloud for years. Worse, it could hit the ocean, vapourizing a large chunk of the world’s water and sending the rest hurtling toward coastlines. One serious strike could do as much damage as a nuclear war. Such strikes have led to mass-extinctions before, as happened to the dinosaurs, and are surely to happen again (if not soon).

There are options – while it’s hard to know whether we’d be successful, it’s not as if our planet has any shortage of nuclear weapons, many of which are already mounted on the same sort of rockets we use for space stations and satellites (ie Soyuz rockets). NASA even managed to hit a comet with a probe, once (and usually manages to hit Mars). The fact that DA14 has been tracked for months and is now a live internet phenomena says a lot – we can now track these threats, and this ability may someday save our planet.

Problem is, that same technology presents us with a very similar threat of fiery global death. Worse, while the odds of an asteroid strike are astronomical in every sense of the word, the threat of a nuclear war is still a clear and present global danger. The old Cold War arsenals are still standing ready at the same launch-on-warning status. They’re smaller now, but still measurable in terms of how many dozen times they could scour the surface of our planet. Declassified documents now show that we came close to a nuclear exchange many times over the years, usually thanks to technical problems. Recent North Korean tests, though terrifying, only represent a tiny fraction of this horrific arsenal and the continuing threat it represents. Asteroids or not, we’d all be a lot safer if every one of these bombs were launched into deep space.

The long term nature of global threats such as an asteroid impact means that any “solutions” we offer need to be sustainable, possibly over millennia. That poses a serious problem for any suggestions based around the current military-industrial complex, which isn’t sustainable in any political, economic or ecological sense of the word. Given the political turmoil almost certain to occur over even the next few centuries, such systems are unreliable at best, and apocalyptic at worst.

As an anarchist, I sincerely hope there isn’t much of a military-industrial complex around in a hundred years. Even for something as noble as the space program, there’s a reason people use the analogy of a peacetime war effort so often. They’re based on the economics of total war, and require an economy of millions to supply the necessary technologies and resources, and of course pay the necessary taxes. Space travel has faced a lot of criticism for these reasons, as well as the millions of lives which could be saved for the fraction of its expense. Though I would still love to see a future which includes space travel, I don’t know that I’d want it to look anything like this.

If space travel is practical enough to someday allow more than a few people off-planet at a time, it’s going to open up some unbelievably frightening possibilities. Almost every science-fiction uses a similar word for a human presence on other worlds: colonies. Talk of asteroid mining is already starting to get serious press in the business world. There’s a serious chance that our species might find a cheap and efficient way into space before we sort out the problems with our expansionist ways. If so, capitalism (or something like it) will be offered an entire universe to consume. Lets not forget what happened last time our civilization found a “new world”.

While I admittedly love Star Trek and other militaristic space operas, I have to say that I’d much rather see the kind of simple, democratized space travel seen in Star Wars. Only time will tell whether either is technologically possible, but it would do us well, as a species, to start thinking about such things now. Like anything else, this is a question of appropriate technology.

In many ways, cuts to the space program may turn out to be a blessing in this respect. There’s no real technical reason the American government couldn’t have sent men to Mars by now, except that they chose to visit spots like Iraq and Vietnam instead. Nevertheless, it’s forced people to look toward far cheaper and more sustainable ways of getting to space, like launching re-usable craft from planes and balloons. Plans once seriously called for interstellar spacecraft propelled by shooting nuclear bombs out their hind ends – now we’re building ultra-efficient ion engines instead. That’s what NASA’s been using to shoot at passing comets, by the way.

In time, we may see other technologies which bring the cost and environmental impact down further. Solar sails are a fascinating option, in theory, able to fly to other planets with almost no fuel. The use of living systems to produce air, food and recycle wastes is also likely to be a pre-requisite. Space travel requires a very high level of sustainability, something which we clearly haven’t mastered on earth, where we have (somewhat) abundant air and water.

Ultimately, our ability to be wiped out by a large rock from space depends on our ability to avoid wiping ourselves out first. Whether or not humanity ever ventures off this rock, we’re going to need to find a way of supporting ourselves which doesn’t leave us with constant threats of dwindling resources and cataclysmic wars. If we don’t, we’re no better than the meteors.