An artist's conception of what Mars could look like as it gradually becomes more habitable. (Credit: Daein Ballard/Wikimedia Commons) Whether it's extreme climate change, an impending asteroid impact, scientific curiosity or even space tourism, there are compelling reasons to think about calling Mars our second home. But before expanding humanity's cosmic real estate holdings, scientists will need to make the Red Planet feel a little more like our blue marble. That, in a nutshell, is the goal of researchers thinking about ways to terraform another planet. Elon Musk, of Tesla and SpaceX fame, has suggested we nuke the polar ice caps on Mars to unlock liquid water and release clouds of CO2 that would thicken the atmosphere and warm the planet. This notion got some press last year when Major League Baseball player and amateur astrophysicist Jose Canseco tweeted: "By my calculations if we nuked the polar ice caps on Mars we would make an ocean of 36 feet deep across the whole planet," thereby enshrining the idea in our popular imagination. Giant mirrors concentrating sunlight on the poles and smashing an entire moon into Mars also top the list of grandiose proposals to Earth-ify the Red Planet. While we may not utilize the kind of cataclysmic forces that some futurists imagine, there are very real efforts, backed up by solid science, currently underway that are building a case for terraforming, one small step for mankind at a time.
Martian Greenhouse
Technically, we're already getting practice terraforming at a planet-wide scale. "There's one solution to terraforming that makes sense when you work out the numbers and it's something that we know how to do," says Chris McKay, a planetary scientist at NASA's Ames Research Center. "And that’s warming the planet by greenhouse gases. That’s basically how we’re warming up the Earth." The basic plan for creating a livable environment on Mars goes like this: Introduce enough greenhouse gases into the atmosphere to begin a cycle of warming, melting the polar ice caps and releasing CO2. This would kickstart a feedback loop of warming as more and more greenhouse gases enter the atmosphere. When the atmosphere thickens and temperatures warm to the point where life could survive, scientists would introduce hardy microbes that would synthesize the gaseous chemicals, beef up the atmosphere and add molecular diversity to the once-barren planet. Over time, we'd plant trees to provide oxygen, and at some point the Red Planet would be fit for human habitation. All that's left is patience. Generations and generations of patience. Based on this plan, McKay estimates that we could fully terraform Mars in about 100,000 years. There are efforts currently under way to study how we might introduce extremophile bacteria and hardy plants to the Martian environment, once the process of warming is under way.
