Sorry, Elon: Nuking Mars’ icecaps won’t geoengineer it
Mars clearly had a warm and wet past, a time when streams, lakes, and even an ocean were present on its surface. Currently, however, most water appears to be locked in its icy poles, and the atmosphere is so thin that water would quickly evaporate off even were temperatures held at Earth-like levels. But could we go back to the future? Is there enough material on Mars to form a dense atmosphere, filled with enough greenhouse gasses to keep things warm enough for liquid water?
Elon Musk attracted a bit of attention when he suggested we could get there simply by nuking Mars’ poles, liberating the ice (both water and carbon dioxide ices) into the atmosphere. When asked about the prospects for the plan, a scientist said, “Whether it would really work, I don’t think anyone has worked up the physics in enough detail to say it would.” Now, a couple of planetary scientists have accepted the challenge of working up the physics, and they have bad news for Elon.
Greenhouse and pressure
The researchers, Bruce Jakosky and Christopher Edwards, focus on two significant questions. The first is whether we can put enough gasses back into the atmosphere to create an Earth-like air pressure, so that people who need to do something on the surface don’t need to wear bulky suits to isolate themselves from the environment. The second is whether we can warm the surface enough so that liquid water could persist on it.