As it could not be otherwise, the inventor of the term was a science-fiction author : the master of space opera Jack Williamson in his work Collision Orbit . According to terraforming expert Martyn Fogg, terraforming is “a planetary engineering process intended to enhance the ability of an extraterrestrial planetary environment to support life. The ultimate goal of terraforming would be the construction of a planetary biosphere that simulates that of Earth.” Land”.
The first serious proposal for terraforming appeared in one of the most prestigious scientific journals, Science , in 1961. Its author was a young scientist and a promising young scientist: Carl Sagan. Sagan’s intention was to turn Venus, a barren planet burning because of a tremendous greenhouse effect, into a new Earth . He assumed that the composition of the planet’s clouds was mostly water vapor, so it would be a good niche for life. So he proposed seeding the clouds with microbial algae, Nostocacae, capable of processing carbon dioxide into oxygen thanks to photosynthesis, thereby reducing the greenhouse effect. This ‘microbiological planetary engineering’, as Sagan called it, has not stood the test of time and today has proven unfeasible. However, we have continued to make progress.
Now, the eyes of space exploration enthusiasts are fixed on Mars, so it is clear that this will be the first planet we will terraform. How we do it?
The first step would be to recreate the primitive atmosphere of Mars, very similar to that of the primitive Earth, through the installation of factories that produce artificial greenhouse gases, such as perfluoromethane (CF4). Thus, if it is released at the same rate that we did with the CFCs on Earth before their ban (a thousand tons per hour) , the average temperature of the planet would increase by 10 degrees in a few decades . This temperature will cause large amounts of carbon dioxide locked up in the Martian regolith to be released, causing the planet to warm even faster. These effects could be increased if we released methane and ammonia-producing bacteria on its surface, since both are powerful greenhouse gases. The net result would be the formation of a Martian atmosphere with more than acceptable atmospheric pressure and temperature. This would be the easy part.
The insolation on Mars will have to be increased by at least 30% to bring it closer to that of Earth. This would be possible through the installation of orbiting mirrors of the solar sail type. We have its basic components in our kitchens: aluminum foil and that thin plastic we use to wrap food. Aluminum is the reflective material; the plastic, the resistant structure on which it is mounted. For example, aluminized mylar is a good “low-tech” material to build those huge mirrors.
Valid levels of nitrogen and oxygen in the atmosphere must then be achieved . To do this, Martyn Fogg proposes the volatilization of nitrates and carbonates through two methods, each one more catastrophic: by directed meteorite impacts or by nuclear mining. Both achieve in situ volatilization of these elements by injecting heat into depth.
Water may seem like a simpler undertaking. With the increase in temperature, the ice that is supposed to exist a few meters below the surface, in the permafrost, would melt. However, there is not enough water there. The only way to add water to Mars is through intense cometary bombardment , something that happened naturally on Earth when it was young. In fact, it is assumed that 30% of the water that exists on Earth today – or almost a third of the water we drink – comes from those comets. This violent Martian transformation would obviously imply an evacuation of human settlements towards the poles.
After 200 years, Mars would have a global temperature of 8ºC, a total pressure of about 240 millibars (the normal pressure on Earth is 1013) and with water running over 10% of its surface with an average depth of 70 m. The small amount of oxygen released into the atmosphere would begin to form enough ozone to stop some of the ultraviolet radiation. Under these conditions, the seeding of algae and other types of aquatic microbial life would be feasible : their survival would be assured at a depth of 10 meters below the water surface.
The most pressing problem at this point in the terraforming is that of nitrogen in the atmosphere. The biological processes that release nitrogen would take thousands of years to reach the levels necessary to make the Martian atmosphere suitable for humans; a totally disproportionate timeframe for a planetary engineering project. But relatively nearby , planetary engineers have a practically inexhaustible source of nitrogen: Titan , Saturn’s moon.
Thus, 500 years after the beginning of the program, humanity will have turned Mars into a new Earth. Unfortunately, maintaining a habitable Mars is absolutely necessary. The control of this artificial biosphere must be the main objective of the future ‘Martians’ and to which they will dedicate the greatest efforts: this is the price to pay for duplicating the Earth elsewhere.
