Mars
Mars is 124 million miles away; it took the Viking spacecraft just over a year to reach it in 1976. On the best estimates, relying upon major improvements in technology, a return journey to Mars would take between one and three years. Nevertheless, the technology now exists for a manned expedition to Mars; what is required is the political motivation. Attempts to generate and maintain interest in the exploration of Mars have been conducted by the Mars Society, who have designed the Martian flag, which is a tricolour, of red, green and blue vertical stripes. Critics have accused the flag design of anthropocentrism, as the colours represent those sensed by human eyes, whereas non-human life-forms are not likely to have the same sensors, which suggests that the same anthropocentrism that dominated nineteenth-century European colonialism is prevalent in the twenty-first century. In reply, it is argued that the three colours, red, green and blue, have a Martian basis, as they represent the three stages of terraforming the planet, where the red signifies its present state, the Martian rock; green represents plant life; and blue represents liquid water. The current scientific goal, however, is to obtain a detailed map of Mars; search for traces of water and signs of former life; and prepare for eventual human exploration.
Proposals for colonizing planets fall under two categories: the first involves the construction of biospheres within which an artificial Earth environment is maintained inside a protective shield to protect its inhabitants from hostile contingencies; the second proposal is more dramatic, involving terraforming – transforming into an Earth-like environment – the planet itself.
Between September 1991 and September 1993 an eight-strong team of men and women survived in Biosphere 2 – a sealed glass and steel structure set on 1.2 hectares of desert in Arizona. Biosphere 2 (Biosphere 1 is the Earth itself) was a closed ecological system, a prototype for eventual life on other planets, particularly Mars. The team had to overcome psychological problems as well as the physical problems of survival, and actually emerged still on speaking terms with each other as well as being physically fit, despite loss of weight due to problems caused by the project’s periodic food crises. Critics pointed out that the hype took over from the science. The project was not strictly self-sufficient; it required supplementary oxygen on at least two occasions. When levels of carbon dioxide became too high, crop harvests were so poor that the inhabitants were short of energy. Moreover, the isolation, which they would have experienced on Mars, was minimized by visitors who were able to communicate from special rooms where they could see and hear each other by means of video cameras. This, of course, could be arranged on Mars. What could not be arranged is the 200,000 tourists who visited the structure each year (Veggeberg, 1993).
Nevertheless, plans for Biosphere 3 are underway. The Mars Society envis-ages a simulated Mars station on Devon Island in the Canadian Arctic. This island is cold and dry, covered with rocky ridges and meteor impact craters, and generally resembles the Martian environment with one exception: the Martian atmosphere is one hundred times thinner than Earth’s. This research station, at
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an estimated cost of US$1 million, will simulate the kind of self-contained and isolated environment that will be encountered by the first human explorers on Mars.
Plans for the actual transformation of planets like Mars are extremely ambitious. The first phase in plans to make Mars fit for humans is to raise the Martian temperature, which is more ambitious than melting Antarctica. This strategy is geared to the creation of a greenhouse effect. The temperature would have to be raised from -60ºC to 0 ºC, which would allow liquid water to settle on the surface. According to one scheme, human settlements or biospheres would be installed on Mars which would house engineers and workers who would build factories on Mars to churn out tonnes of greenhouse gases each year, thus trapping heat in the atmosphere. These would be the very same gases which are destroying the ozone layer on Earth. This would be a big project, employing tens of thousands of workers, but chlorofluorocarbons (CFCs) are composed of carbon, fluorine and chlorine, which are known to exist on the Martian surface. It may only require a little initial effort from humans; once a greenhouse effect is underway other greenhouse gases, such as CO2, would be released, thus contributing to the runaway effect that has been predicted from studies of models of the Earth’s climate.
Among the schemes for the greening of Mars are proposals to melt the northern polar ice-cap by scattering carbon black pigment over its surface to enable the solar rays to be absorbed, rather than reflected. Dark soot could be mined from two small moons orbiting Mars. Other proposals include the erection of giant mirrors in space to re-direct the heat of the Sun. This melting would then create a greenhouse effect in which carbon dioxide and water vapour would be released into the atmosphere to raise the surface temperature. Water could be imported from the asteroids if there is not enough native water. Moreover, there are many icy objects of considerable size beyond the planet Neptune. If their orbits were tilted towards Neptune for gravity assistance and then aimed at Mars, they might provide an adequate supply of water for human settlements (Johansson, 1998: 53). According to estimates (Nadis, 1994; Zey, 1994), after about 200 years a wetter, warmer Mars would possess a thicker atmosphere, more tolerable for humans.
The second phase is estimated to take a great deal longer, about 100,000 years (Nadis, 1994), and would involve the production of oxygen of sufficient quantity for humans to breathe on the planet. Thus, when the planet has warmed, certain organisms – for example, the blue-green algae found on Earth – could be planted. At present Martian soil lacks oxygen, nitrogen and phospho- rous. But the planting of lichens and blue-green algae, if successful, would help to produce oxygen. Once underway, genetically altered plants and self-replicating micro-organisms could be added in order to speed up the process. As the atmosphere becomes thicker the planet would become warmed. Carbon dioxide, nitrogen and water would seep from the crust. Lakes and small oceans would appear. Rocks could be mined for iron oxide which could be heated to
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