Free Astronomy Magazine September-October 2018

45 SEPTEMBER-OCTOBER 2018 PLANETOLOGY T erraforming Mars is for now just a game for kids. This fun pastime, re- leased in 2016 by FryxGames, and integrated with some more recent expansions, is an ideal tool to bring young peo- ple closer to im- portant issues. [Enoch Fryxelius, FryxGames, Vel- linge, Sweden] sufficient to guarantee the terraforming of Mars. Here is how Jakosky summarizes the situation: “Our results suggest that there is not enough CO 2 on Mars to provide signifi- cant greenhouse warming were the gas to be put into the atmosphere; besides, most of the CO 2 gas is not accessible and could not be readily mobilized. As a result, ter- raforming Mars is not possible using pres- ent-day technology” . In conclusion, the only thing we can realis- tically do (perhaps) is to try to consolidate the current Martian atmosphere, prevent- ing the dispersion with an artificial magnetos- phere and leaving the natural geological de- gassing, produced by the residual geologi- cal activity, the task of raising the pressure on the surface. But this process is so slow that we will have to wait tens or hundreds of millions of years to transfer the popula- tion surplus to Mars. How many might we be in that distant fu- ture? The results say that even if we were able to vaporize all the CO 2 contained in the two polar ice caps, we could only double the at- mospheric pressure (from 0.6 mbar to 1.2 mbar). If we succeeded in freeing the CO 2 embedded in the dust of the Martian soil, we would get no more than 4% of the op- timal pressure. Other small percentages would be added by releasing CO 2 contained in subsurface mineral deposits, under- ground water ice reserves and clathrates. Taken together, all these possible sources of CO 2 (and other less relevant gases) are not !