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earth Bis

the Sun is going to destroy us. that’s for sure. For billions of years it has fed and maintained us, but what used to be our support will be the source of our death. as a result of natural processes which occur inside the Sun, its temperature is higher and higher. In a few billions of years, the Sun will start to swell, first burning the Earth and then absorbing it. What is going to happen to us then?

If we do not find a way to run away from the Earth – we will die. And if we are to flee, the question is where? And how? Will we manage on a foreign, unfriendly globe? the globes which are within our reach today are indeed unfriendly. there is virtually no atmosphere on Mars, and – except for the poles – it is uncertain if there is any water. and even if there was, there is no food or plants.

It was obvious that men will fly to the Red Planet one day. The first step was the Moon. It is close, which is its basic advantage. Mars will be the next one because, unlike in the case of our satellite, people may function on Mars. In spacesuits and in masks, of course, but still in conditions more similar to the terrestrial ones than to the conditions on the Moon. Mars is very much like the earth, both geologically and historically. there may have been some rivers, lakes and oceans here before. What has become of them? Most of them have probably evaporated, but there is a chance that there is a lot of water under the surface of the Martian soil. Permafrost is waiting to be extracted. and when it works out, we will have – as mankind –one foot on the Red Planet. The first people flying to Mars will most likely take large supplies of food, but if anyone is seriously thinking of settling the planet (even if it was to be only a permanent scientific base), they must find a way to produce food there, locally. It would be necessary to grow plants whose DNA would be modified in such a way that they may grow in the Martian soil and in extremely thin atmosphere. But is it feasible? and can it be checked on the earth? and maybe instead of testing the Martian conditions on the earth, it would be better to recreate terrestrial conditions on Mars?

It is easy to say but how can it be done? the atmospheric composition is not constant but it is a fact that its changes are very slight (from the human time perspective). Within

the last several dozen years we managed to “fill” the Earth’s atmosphere with quite a lot of CO2. as a consequence, our atmosphere is getting warmer. therefore would it be possible to change the composition of the atmosphere on Mars in a similar way? So that it is possible to live there? It would be extremely complicated for many reasons. First, Mars is much lighter than the earth, forming it’s atmosphere by attracting gas particles using the planet’s gravitation but with a smaller force. unfortunetly, will not be able to increase the planets mass. Besides, Mars (unlike the Earth) does not have a magnetic field, which works like an umbrella and protects the atmosphere from a large amount of particles flying from the surface of the Sun. these particles may blow off the atmosphere. It is, in principle, impossible on the earth. and it is a real threat on Mars. It might turn out that the produced (in some way) atmosphere would be destroyed at the first opportunity. Yet, where there’s a will there’s a way. Maybe it will be possible in the future to create a device which would be the source of an artificial magnetic field. Apart from such objective difficulties, would we manage to create atmosphere on a foreign globe? theoretically yes. Such a process is called terraforming. It has not been conducted so far but we know nevertheless that “production” of atmosphere, for example with the use of bacteria, would take hundreds of thousands, or at least tens of thousands of years. In the case of Mars, it would first need to be heated, for example by increasing the amount of CO2 in the Martian atmosphere. Higher temperature would melt frozen water on Mars. Plants could grow on moist ground. They would absorb CO2 and produce oxygen. It sounds very simple. But, believe me, it wouldn’t be simple at all. the atmosphere is a system of many interconnected vessels. We do not fully understand the mechanisms that rule it. The creation of an artificial atmosphere somewhere or a drastic change of its composition in a controlled way and intentionally is not science fiction. It is fiction.

It is best proved by the results of the Biosphere 2 experiment. the idea was simple. In order to settle other globes it is necessary to build a self-sufficient base on them. Its inhabitants had to be able to grow plants and breed animals in numbers allowing not only for survival but rather for long-term functioning. trees were to turn the carbon dioxide exhaled by men, animals and produced by bacteria into life-giving oxygen, and sunlight was to be the only external factor. The proliferation of flora was to be regulated by the amount of nutritious substances in the soil and carbon dioxide in the air, and animals were to reproduce as long as there was enough food and oxygen to breathe. the same was planned for water plants. It was believed – not groundlessly – that when nutritious substances in water run out, algae, plants and fish will simply stop reproducing. And even if some plants grow too much, there should be more fish which will simply eat the excess of water plants. In brief, the plan was to build a self-sufficient and self-regulating ecosystem or, in other words, to create “another Earth” (hence the “two” in the project name) somewhere in outer space. Without going into details of the projects – it did not work out. In retrospect, it is certain that Biosphere 2 did not fail because of high costs. the project failed right at the beginning because it was believed that we understand how the earth’s ecosystem works. and, in reality, we are groping in the dark in many respects.

and what about terraforming? If we are unable to build a system of greenhouses for all, maybe it is worth looking once more at the idea of terraforming. When examining our terrestrial extremophiles, that is bacteria living in the most unfavourable places on the globe, we may, without a doubt, say that our terrestrial microbes would manage without any problem on the red Planet. and this is important because bacteria might gradually recreate the Martian atmosphere and fertile ground. the process would, however, take a long time. the recreated gas envelope would allow for the functioning of more and more complex organisms. With time, it would be possible to plant trees. If oxygen concentration was high enough, people might move to the red Planet. But is terraforming of Mars the future of mankind? If we want to try to adjust some globes, it would be better to tackle something located further from the Sun than Mars. When the earth starts to boil in the rays of sunshine, life on Mars will become unbearable. How about the moons of Jupiter or Saturn? Or maybe we can find by that time a way to travel to globes situated in other planetary systems.

Tomasz Rożek, PhD Physicist, populariser of science, author of the TVP programme “Sonda 2”

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