| 
 | 
| 
 
 
			from
			
			TheTerraformingInformationPages 
			Website 
 
 
 
			 
			York University, Toronto, Canada 
			 
 The latter devices cannot be inhabited indefinitely; for lengthy stays the crews sooner or later become dependent on resupply missions from Earth. Recently, the President of the United States called for the establishment of bases for astronauts on the moon and Mars. The first human outposts in space will, of necessity, be of the second kind, even though some local resources may be exploited by their occupants. 
 
			Human settlements on other planets can 
			become fully and permanently independent of Earth only of these 
			distant environments are transformed to provide Earth-like living 
			conditions and a local agriculture. The realistic possibilities for 
			this latter type of planetary engineering, carried out on a global 
			scale, are assessed briefly in this essay. 
 
			We are exotic products of a planetary 
			engine originally set in motion, and continuously fuelled, by energy 
			from the sun. 
 Though presently barren, Mars, nonetheless, is a biocompatible planet. Its unalterable physical characteristics (e.g. size, density, gravity, orbit, rotation rate, incident sunlight) and its possible chemical resources are remarkably consistent with life. Indeed, it was the hope that organisms might be found on Mars that made life-detection the top priority for NASA’s Viking missions in 1976. 
 
			However, all of the ingenious biological 
			experiments carried out by the two robotic landers gave negative 
			results. 
 This thin atmosphere consists of 95% carbon dioxide and 3% nitrogen, with only trace amounts of water vapour, oxygen and other gases. There is no protective ozone layer to shield the planet from the ultraviolet radiation emitted by the sun. Most surprising was the absence from the soil of any detectable organic molecules, the building blocks of life. 
 
			Even though such materials arrive on 
			Mars in meteorites, they are subsequently destroyed, at least on the 
			surface of the planet. Thus, any organisms which might arrive there 
			unprotected today would be freeze-dried, chemically degraded, and 
			soon reduced to dust. It would not be possible to ‘seed’ Mars just 
			by sprinkling bacteria over its surface. 
 
			A major uncertainty in these discussions 
			is whether there remains on Mars today adequate amounts of carbon 
			dioxide, water and nitrogen to allow such a planetary-scale 
			transformation. If most of Mars’ original endowment of these 
			materials has been lost to space, then the regeneration of a 
			habitable state would be impossible. 
 This atmosphere would be warm and moist, and water would flow again in the dried up river beds. The average temperature at the surface would rise to about 15 degrees Celsius and the atmospheric pressure would be roughly twice that on Earth. Appropriately selected, or genetically engineered, anaerobic microorganisms, and eventually some plants, could grow under these conditions. 
 
			If future exploration reveals that the 
			necessary volatiles are indeed available then a new home for life 
			might someday be created on our sister planet. 
 Obviously, this would not provide an environment in which animals or humans could survive outdoors. All oxygen-dependent organisms transported to Mars would have to remain enclosed in life-support modules or appropriate protective gear. The word ‘terraformation’ is used to describe the formation of specifically Earth-like, aerobic conditions on planets. Such a salubrious environment is only one of many possible long-term and not necessarily inevitable, outcomes of ecopoiesis. 
 If we consider the spontaneous development of Earth’s biosphere as a model for what might be achieved by design on Mars, terraformation would have to be initiated subsequently to ecopoiesis. If we restrict our speculations to plausible, near-term technologies, the time periods required to carry out ecopoiesis and terraformation on Mars are very different. If suitable volatile inventories exist, the thick, warm atmosphere described above might be generated in as little as 200 years. 
 
			However approximately 100,000 years 
			would be required if an oxygen atmosphere was to be produced as 
			efficiently as it was on Earth, that is, by microbial and green 
			plant photosynthesis. However, it remains possible that presently 
			unimagined, futuristic technologies could be developed to shorten 
			these time estimates considerably. 
 
			For example, do humans have any right to 
			‘play God’ on another planet? 
 However, in an amazing biotic diaspora, microrganisms, followed by plants and animals, migrated from marine to fresh water environments and then onto the initially barren land. None of this would have been possible were it not for the evolutionary development, by living cells, of the ‘technology’ of photosynthesis. Essentially all of the free oxygen (and the resulting ozone shield) in Earth’s atmosphere was, and is, generated by photosynthesis. 
 
			Even though oxygen is poisonous to most 
			anaerobic organisms, its accumulation in the atmosphere created the 
			conditions necessary for the flowering of aerobic life as we know it 
			today. 
 
			Rather, it has been the amazingly rapid 
			and efficient processes of social and technological evolution which 
			have facilitated the propagation of our species, across every 
			continent, and most recently into space. 
 Against this background it is not just an idle dream to imagine that people might yet "slip the surly bonds of Earth" to pioneer new habitats in the sky. Further exploration of Mars may well reveal that ecopoiesis is feasible on that planet. Such a discovery would provide future generations with a tremendous challenge in life and an exhilarating vision of the role of humankind as a participant in creation. 
 Perhaps however, there are also deep psychological and biological reasons for seeking to enliven Mars: such a vast enterprise would surely be consistent with the Promethean myths of many cultural traditions and the proliferative imperative that animates life itself. 
			 
 |