Let’s say we want to colonize Mars. Or better yet, let’s say we need to colonize Mars. After all, world-renowned astrophysicist Stephen Hawking—a rather smart fella, if ever there was one—has said humanity will face a choice between space colonization and extinction. Speaking to Canadian Press in November, Hawking said that because our genetic code carries in it selfish instincts, which made sense for survival thousands of years ago, it willl be difficult “to avoid disaster in the next hundred years, let alone the next thousand or million.” In short, we’ve outpaced evolution and we’ve got all our eggs in one basket: Earth.
But why Mars? For one, it’s close by, comparatively speaking. Mars’s surface area may only be a third that of Earth’s, but keep in mind two-thirds of our planet is covered by water. Mars also has an atmosphere, albeit a thin one. Indeed, the red planet is generally considered the most Earth-like in our solar system. Even the days are only 40 minutes longer than ours.
But is it really doable?
The colonization of Mars should be viewed as an ongoing process. Despite its similarities to Earth, humans wouldn’t last long on its surface. With only trace amounts of oxygen in its atmosphere, you’d be lucky to live a couple minutes, if the cold doesn’t kill you first (the average temperature on Mars is -63°C). Still, that’s not nearly as bad as other planets. Venus, thanks to a runaway greenhouse effect, is a toasty 462°C. Nonetheless, full-body spacesuits would be required for early Martian pioneers.
In a sense, the colonization of Mars has already begun. Since the ‘60s, we’ve sent dozens of robots, including a handful of rovers, which could be used to locate resources and the environments most suitable for colonization. And while early manned missions would likely be purely exploratory, stations for long-term stays could eventually be built.
Protected colonies may lead the way—think giant space bubbles—but the endgame will likely be terraforming. That is, changing the planet’s environment to become extremely Earth-like, to the point of being livable. It’s an ambitious goal, to say the least. But planetary scientist Christopher McKay and aerospace engineer Robert Zubrin have studied and written extensively about the potential for turning Mars’s environment into a habitable one, and they’re optimistic. They point out that Mars used to have a warm, wet climate and a thick atmosphere, and they believe this could be recreated “using 21st century technology.”
Step one would be to heat up the atmosphere. We can’t move Mars to a hotter orbit, but there is another way to warm a planet: triggering a greenhouse effect that would trap more of the sun’s energy. There are a few ways to do this, but one idea includes building giant space mirrors that would reflect heat onto the planet’s south pole, home to a heck of a lot of frozen CO2. If that CO2 were turned back into gas, the atmosphere would thicken and the climate warm.
It could get to a point, argue McKay and Zubrin, where pressure suits would no longer be needed—only oxygen masks. “With outside atmospheric pressures raised, it will be possible to create large dwelling areas by means of very large inflatable structures,” they write in a journal article titled “Technological Requirements for Terraforming Mars.” Under these warmer conditions, plants, which produce oxygen, could be grown, though it could take thousands of years before animals could dwell on the surface unaided. Speeding up the oxygenation process still requires a big leap in technology.
But even if that part takes a while, imagine this: a Mars with unfrozen water, turned into rivers, lakes and maybe even small seas; a Mars with a tolerable climate and an adequately thick atmosphere; a Mars with grass and plants. This vision of the red planet may not be so out of reach—at least technologically.
There are, of course, other hurdles. Like money. The space mirrors McKay and Zubrin imagine would have a radius of 100 kilometres, and can’t be cheap. With money, it becomes a matter of how badly do we want it—or need it. The former is more difficult to answer, but for the latter, assuming Stephen Hawking is right about our species, the correct response may be pretty badly, pretty soon.