Terraforming Mars

Artificial greenhouse gases that are bad news on Earth could provide the means to make Mars a more comfortable place for humans to live.

To say that Mars is a chilly place would be an understatement. The Red Planet's mean annual temperature is 55 degrees C below zero - that's about the same as the temperature of Earth's south pole during winter.

If humans ever build communities on Mars, they might want to find a way to turn up the global thermostat. At a NASA-sponsored conference, "The Physics and Biology of Making Mars Habitable", scientists discussed ways that future colonists might make the frigid planet a little more comfortable.

One solution might be to pump enough greenhouse gases into the Martian atmosphere to create a runaway greenhouse effect. Here on Earth, the idea of a runaway greenhouse sets off alarm bells. But on Mars it could be a plus. Scientists at the conference speculated how it might be possible to warm Mars just enough to evaporate the planet's available carbon dioxide (CO2 trapped in ices and frost) into the atmosphere, where such gases could contribute to keeping the planet warm.

But there are two problems. First, even if all of Mars's available CO2 were coaxed into the atmosphere, it wouldn't necessarily warm the planet enough to make it a comfortable place for humans, because no one knows just how much CO2 is there. Second, the best way to get Mars to release its CO2 spontaneously is, well... to warm it up. It's a "Catch-22" situation!

Margarita Marinova, an undergraduate student at MIT, believes she has an answer to both problems. Use artificially created perfluorocarbons (PFCs) to initiate the planetary warming process. Marinova has been studying the warming effects of PFCs, in collaboration with Chris McKay, a member of the NASA Astrobiology Institute at the Ames Research Centre. McKay was one of the organisers of the terraforming conference where Marinova presented her research.

PFCs have several advantages. First, they are super-greenhouse gases. A little bit does a lot of warming. Second, PFCs have a very long lifetime. This causes serious problems on Earth, but their longevity would be a positive factor on Mars. Third, they do not have any negative effects on living organisms.