Their study focused on fluorine-based gases, composed of elements readily available on the Martian surface, that are known to be effective at absorbing thermal infrared energy. They found that a compound known as octafluoropropane, whose chemical formula is C3F8, produced the greatest warming, while its combination with several similar gases enhanced the warming even further.
The researchers anticipate that adding approximately 300 parts per million of the gas mixture in the current Martian atmosphere, which is the equivalent of nearly two parts per million in an Earth-like atmosphere, would spark a runaway greenhouse effect, creating an instability in the polar ice sheets that would slowly evaporate the frozen carbon dioxide on the planet’s surface. They add that the release of increasing amounts of carbon dioxide would lead to further melting and global temperature increases that could then enhance atmospheric pressure and eventually restore a thicker atmosphere to the planet.
Such a process could take centuries or even millennia to complete but, because the raw materials for the fluorine gases already exist on Mars, it is possible that astronauts could create them on a manned mission to the planet. It would otherwise be impossible to deliver gigaton-sized quantities of the gas to Mars. The authors conclude that introducing powerful greenhouse gases is the most feasible technique for raising the temperature and increasing the atmospheric pressure on Mars, particularly when compared to other alternatives like sprinkling sunlight-absorbing dust on the poles or placing large mirrors in the planet’s orbit.
Text for this article comes from a AGU press release.
I first started thinking about nuking Mars to warm it up back when I was working at Oak Ridge. Just for the record, here’s some interesting facts and figures on that topic.
The Margarita Marinova link above suggests 100 greenhouse gas factories working 100 years each could raise the temp of Mars by 6 – 8 degrees per century. Who’s got that kind of time to waste? Not me. I say nuke ’em til they glow.
The atmosphere of Mars contains around 2.5 X 10 ^ 16 kilograms of gas which is around 95% carbon dioxide. The specific heat of carbon dioxide is around 0.15 to 0.20 calories per gram per degree C depending on whether you’re holding the volume or pressure of the gas constant while you’re heating it. Going with the higher number means that to heat the atmosphere of Mars one degree C requires ( 2.5 * (10^16) kg ) * (1000 g / kg) * ( 0.2 cal / g) = 5 * 10 ^ 18 calories. There’s a little more than 4 calories in a joule, so let’s say it takes roughly 1 * 10 ^ 18 joules to raise the Martian atmosphere by 1 degree C.
A megaton of TNT (the traditional unit by which nuclear weapons are measured) is equivalent to around 4X10^15 joules. The biggest nuke out there (at least that I’m gonna talk about here on SciScoop – my Q clearance is long gone but what happens in Oak Ridge stays in Oak Ridge) is (was) the 50 – 100 MT Soviet Tsar Bomba. Thus a single souped-up 100 MT hydrogen bomb can deliver 400 * 10 ^ 15 joules which is equivalent to 0.4 * 10 ^ 18 joules.
So, detonating on Mars the biggest nuke ever made would raise the Martian atmosphere temperature by a half-degree C. Umm, you really wouldn’t want to do that, since it was a three-stage plutonium fission – fusion – U238 fission design that put out absolutely horrendous amounts of fallout. Still, if (read : when) we come up with a clean fusion only bomb design that made use of our vast existing stockpiles of lithium-6-deuteride, we could raise the temp of Mars as much as we wanted in just a few hours. Let’s see, a half-degree per nuke times the Cold War inventory peak of 30,000 nukes…
I think terraforming Mars by warming it up may well happen a lot faster and sooner than most people think. It would be worth doing just to watch the fireworks and resulting sandstorm from orbit.
There also is the long-suggested method of bombing Mars with asteroids and comets. Drop carbon-containing rocks for carbon dioxide (if the impact and heat will provide enough oxygen). Drop water ice for water vapor (which causes most of Earth’s natural greenhouse effect).
Or perhaps one could drop the carbon on a pole and hope it didn’t oxidize. Organics tend to be dark, and the decreased albedo of an organic layer on top of the ice would quickly melt it during summer.
3 days late, and hugely commented. This story has reached /. and it is one of the most commented science stories in recent memory.