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Life on Mars Tapping, Ken

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Publisher’s version / Version de l'éditeur: https://doi.org/10.4224/23004533 Skygazing: Astronomy through the seasons, 2018-10-16

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Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n’arrivez pas à les repérer, communiquez avec nous à [email protected]. LIFE ON MARS can drink it, and using locally available solar energy, unless there is a dust storm, we can break Ken Tapping, 16th October, 2018 down that water to get oxygen to breathe. On the One day, sooner or later, we will be living on Mars, other side, building a warm habitation in or on the either as visitor explorers and scientists, or as Martian surface could cause the same problems colonists. It might take a while, but if the will is as we get in the Arctic if we do something that there, our technology will get us to where it melts the permafrost. We will have to locate our becomes economically and logistically feasible. habitations very carefully, otherwise they could end up collapsing in pools of meltwater. Mars presents a challenge. Its atmosphere is so thin we will need almost a space suit to move Stays of weeks or months in Earth orbit or on the around outdoors. What atmosphere there is Moon are very different from the long journey consists mostly of nitrogen. It is not toxic, but it is times involved in getting to Mars, and the long of no use to us. There are some other problems. stays on Mars made necessary by waiting until The thin atmosphere means that there is little Mars and Earth are in the right position for the greenhouse effect to trap heat, so daily return trip. Our environmental needs become temperatures vary enormously. During the summer larger. In addition to the need to meet nutritional it can get above freezing during the day and then and sanitary requirements, there is the problem go down to 100 Celsius or more below at night. that we constantly shed flakes of skin, oily sweat, Even though Mars is further from the Sun than the hair, and so on. On Earth we are surrounded by Earth is, the lack of any significant atmosphere living things, such as bacteria and dust mites, means more solar ultraviolet radiation reaches the which deal with and recycle them, stabilizing our surface. In addition Mars has no global magnetic ecosystem. Otherwise they will accumulate behind field. This, together with the lack of atmosphere panels and in nooks and crannies, becoming food means other high-energy radiation can reach the for bacteria and fungi, making us sick. The longer surface of the planet. It could be that living things we are away from home, the more of our might have appeared a billion or more years ago, ecosystem we will have to take with us. when Mars was warm and wet, but now, with the These days we talk or dream about “terraforming” planet being an almost airless, frozen desert, if worlds, changing their atmosphere and other anything survives, it must be hiding underground. conditions so that we can set up an entire For a long time our visions of colonies on Mars ecosystem to suit us, and can live with little or no and similar worlds have been of life under inflated, technical assistance. These are at the moment just clear plastic bubbles. Inside you get the sunlight ideas. Of course, whether we end up terraforming and if the bubbles are made of the right material, Mars depends on one other issue. If there are still the greenhouse effect will provide some solar any surviving Martians, we should leave things heating. However, the thin plastic will have little alone. They might not want us to do it. insulation value against low temperatures outside, Jupiter is lost in the sunset glow. Saturn lies low in and warm rising air would be cooled off. It also the south–southwest after dark and Mars is still offers little protection against radiation. A more bright in the south-southeast. The Moon will reach realistic approach would be to build habitations First Quarter on the 16th and be Full on the 24th. underground, where a few metres of soil would provide insulation against temperature variations Ken Tapping is an astronomer with the National and screening against radiation. However, an Research Council's Dominion Radio Astrophysical interesting dimension here is that there is a lot of Observatory, Penticton, BC, V2A 6J9. ice under the Martian surface. On one side it Tel (250) 497-2300, Fax (250) 497-2355 means we will have locally available water. We E-mail: [email protected]