“You can transform Mars into an Earth-like planet. You’d warm it up,” Elon Musk famously told late night host Stephen Colbert a few years ago, regarding his plans for colonizing the red planet. After saying there was a fast way and a slow way to do this, and being asked what the fast way was, the Tesla and SpaceX chief replied: “The fast way is to drop thermonuclear weapons over the poles.”
The basis of this and other plans to “terraform” Mars is to release carbon dioxide and water vapor into the Martian atmosphere, then wait for the resulting greenhouse effect to warm things up enough to support water in its liquid form, and thus life. Nuking the planet’s polar caps would be one way to release those gases.
However, the plan wouldn’t work, according to the authors of a NASA-sponsored study published Monday in the journal Nature.
In the paper, Bruce Jakosky of the University of Colorado, Boulder, and Christopher Edwards of Northern Arizona University, Flagstaff, pointed out that Mars simply doesn’t have enough carbon dioxide to make the plan viable.
The study is based on spacecraft observations of Mars over the last couple decades, taking in data on carbon-bearing minerals and the levels of carbon dioxide in the planet’s polar ice.
“Our results suggest that there is not enough CO2 remaining on Mars to provide significant greenhouse warming were the gas to be put into the atmosphere; in addition, most of the CO2 gas is not accessible and could not be readily mobilized. As a result, terraforming Mars is not possible using present-day technology,” said Jakosky in a statement.
The scientists noted that there’s plenty of water vapor locked up in Martian polar ice, which could be released by “spreading dust on it to absorb more solar radiation”—or, yes Elon, through explosions—but there’s only enough carbon dioxide in there to double the Martian atmospheric pressure to a mere 1.2% of Earth’s.
Heating the Martian soil could add another 4% to the pressure, while a little more could come from unlocking the carbon in mineral deposits. But even then, based on the evidence we have today, we’d be unable to get anywhere close to the atmospheric conditions needed to stop that unlocked CO2 and water vapor just wandering off into space.
How about redirecting comets and asteroids at Mars (what could go wrong?) in order to aid the effort? Even that wouldn’t work, the authors said, noting that “many thousands” would be needed.
In short, given current and foreseeable technology, any colonization of Mars is going to require proper life support rather than a congenial atmosphere.