Terraforming Mars And Greenhouse Gases
NASA Ames Research Center
TodayÕs Mars is too cold and its atmosphere too thin to sustain Earth life. In the process of ecopoiesis, then, the first step should be to warm up Mars. When sunlight hits the Martian surface, it is converted into thermal infra red radiation, which is then radiated out. Since Mars has a very thin atmosphere, most of this energy is lost into space. In EarthÕs atmosphere, it is gases such as carbon dioxide, water, ozone, and more recently artificial greenhouse gases that trap the radiation within the atmosphere and therefore warm up the planet. On Mars, similar gases can be used. Carbon dioxide and water vapor are the most prominent greenhouse gasses on Earth, however they leave a "window" region in the 8-12 mm range, where they do not absorb thermal IR. Artificial greenhouse gasses can be used to cover the window region and for overall heat retention. A good greenhouse gas for Mars would require that all the constituent elements are abundant on Mars, it is easy to produce, it has a long life-time in the Martian atmosphere, and it has no negative effects. Considering all these factors, the best molecules are C2F6, CF4, and SF6. Estimates have shown that even at a few parts per million, greenhouse gasses will warm up Mars by about 20*C. In this study, the transmission spectra of C2F6, CF4, and SF6 were quantitatively measured, in order to accurately calculate the greenhouse warming of Mars, given different mixtures and concentrations of the gases. Preliminary results show strong absorption bands for C2F6 in the 5.5-6 mm, 7.1-9.3 mm, 13.5-15.2mm, and 17.2-21.0mm ranges. This already shows the gasÕ property as a good greenhouse gas and itÕs role in covering the window region.