Terraforming - building a new Earth in a new place

One day it may turn out that in the event of a global catastrophe, it will not be possible to restore civilization on Earth or return to the state in which it was before the threat. It is worth having a new world in reserve and building everything anew there - better than we did on our home planet. However, we do not know of celestial bodies ready for immediate settlement. One has to reckon with the fact that some work will be required to prepare such a place.

1. Cover of the story "Collision in Orbit"

Terraforming a planet, moon, or other object is the hypothetical, nowhere else (to our knowledge) process of changing the atmosphere, temperature, surface topography, or ecology of a planet or other celestial body to resemble Earth's environment and make it suitable for terrestrial life.

The concept of terraforming has evolved both in the field and in real science. The term itself was introduced Jack Williamson (Will Stewart) in the short story "Collision Orbit" (1), published in 1942.

Venus is cool, Mars is warm

In an article published in the journal Science in 1961, the astronomer Carl Sagan proposed. He envisioned planting algae in his atmosphere that would convert water, nitrogen, and carbon dioxide into organic compounds. This process will remove carbon dioxide from the atmosphere, which will reduce the greenhouse effect until the temperature drops to a comfortable level. Excess carbon will be localized on the surface of the planet, for example, in the form of graphite.

Unfortunately, later discoveries about the conditions of Venus have shown that such a process is impossible. If only because the clouds there consist of a highly concentrated solution of sulfuric acid. Even if algae could theoretically thrive in the hostile environment of the upper atmosphere, the atmosphere itself is simply too dense—the high atmospheric pressure would produce almost pure molecular oxygen, and the carbon would burn, releasing COXNUMX.₂.

However, most often we talk about terraforming in the context of the potential adaptation of Mars. (2). In an article "Planetary Engineering on Mars" published in the journal Icarus in 1973, Sagan considers the Red Planet to be a potentially habitable place for humans.

2. Vision for the next stages of terraforming Mars

Three years later, NASA officially addressed the problem of planetary engineering, using the term "planetary ecosynthesis". A published study concluded that Mars could support life and become a habitable planet. In the same year, the first session of the conference on terraforming, then also known as "planetary modeling", was organized.

However, it wasn't until 1982 that the word "terraforming" began to be used in its modern sense. planetologist Christopher McKay (7) wrote "Terraforming Mars", which appeared in the Journal of the British Interplanetary Society. The paper discussed the prospects for the self-regulation of the Martian biosphere, and the word used by McKay has since become the preferred one. In 1984 James Lovelock i Michael Allaby published the book Greening Mars, one of the first to describe a new method of heating Mars using chlorofluorocarbons (CFCs) added to the atmosphere.

In total, a lot of research and scientific discussions have already been carried out about the possibility of heating this planet and changing its atmosphere. Interestingly, some hypothetical methods for transforming Mars may already be within the technological capabilities of humanity. However, the economic resources required for this will be far greater than any government or society is currently willing to allocate for such a purpose.

Methodical approach

After terraforming entered into a wider circulation of concepts, its scope began to be systematized. In 1995 Martin J. Fogg (3) in his book "Terraforming: Engineering the Planetary Environment" he offered the following definitions for various aspects related to this field:

• planetary engineering - the use of technology to influence the global properties of the planet;
• geoengineering - planetary engineering applied specifically to the Earth. It covers only those macro-engineering concepts that involve changing certain global parameters such as the greenhouse effect, atmospheric composition, solar radiation, or shock flux;
• terraforming - a process of planetary engineering, aimed, in particular, at increasing the ability of an extraterrestrial planetary environment to support life in a known state. The final achievement in this area will be the creation of an open planetary ecosystem that mimics all the functions of the terrestrial biosphere, fully adapted for human habitation.

Fogg also developed definitions of planets with varying degrees of compatibility in terms of human survival on them. He distinguished the planets:

• inhabited () - a world with an environment similar enough to Earth that people can comfortably and freely live in it;
• biocompatible (BP) - planets with physical parameters that allow life to flourish on their surface. Even if they are initially devoid of it, they can contain a very complex biosphere without the need for terraforming;
• easily terraformed (ETP) - planets that can become biocompatible or habitable and can be supported by a relatively modest set of planetary engineering technologies and resources stored on a nearby spacecraft or robotic precursor mission.

Fogg suggests that in his youth, Mars was a biologically compatible planet, though it currently doesn't fit into any of the three categories - terraforming it is beyond ETP, too difficult, and too expensive.

Having an energy source is an absolute requirement for life, but the idea of ​​a planet's immediate or potential viability is based on many other geophysical, geochemical, and astrophysical criteria.

Of particular interest is the set of factors that, in addition to the simpler organisms on Earth, support complex multicellular organisms. animals. Research and theories in this area are part of planetary science and astrobiology.

You can always use thermonuclear

In its roadmap for astrobiology, NASA defines the main criteria for adaptation as primarily "adequate liquid water resources, conditions conducive to the aggregation of complex organic molecules, and energy sources to support metabolism." When conditions on the planet become suitable for the life of a certain species, the import of microbial life can begin. As conditions become closer to terrestrial, plant life may also be introduced there. This will speed up the production of oxygen, which in theory will make the planet finally able to support animal life.

On Mars, the lack of tectonic activity prevented the recirculation of gases from local sediments, which is favorable for the atmosphere on Earth. Secondly, it can be assumed that the absence of a comprehensive magnetosphere around the Red Planet led to the gradual destruction of the atmosphere by the solar wind (4).

4 Weak Magnetosphere Doesn't Protect Martian Atmosphere

Convection in the core of Mars, which is mostly iron, originally created a magnetic field, however the dynamo has long ceased to function and the Martian field has largely disappeared, possibly due to core heat loss and solidification. Today, the magnetic field is a collection of smaller, local umbrella-like fields, mostly around the southern hemisphere. The remnants of the magnetosphere cover about 40% of the planet's surface. NASA Mission Research Results Specialist show that the atmosphere is being cleared primarily by solar coronal mass ejections that bombard the planet with high-energy protons.

Terraforming Mars would have to involve two large simultaneous processes - the creation of an atmosphere and its heating.

A thicker atmosphere of greenhouse gases such as carbon dioxide will stop the incoming solar radiation. Since the increased temperature will add greenhouse gases to the atmosphere, these two processes will reinforce each other. However, carbon dioxide alone would not be enough to keep the temperature above the freezing point of water - something else would be needed.

Another Martian Probe That Recently Got a Name Perseverance and will be launched this year, will take trying to generate oxygen. We know that a rarefied atmosphere contains 95,32% carbon dioxide, 2,7% nitrogen, 1,6% argon, and about 0,13% oxygen, plus many other elements in even smaller amounts. The experiment known as pep (5) is to use carbon dioxide and extract oxygen from it. Laboratory tests have shown that this is generally possible and technically feasible. You have to start somewhere.

5. Yellow modules for the MOXIE experiment on the Perseverance rover.

spacex boss, Elon Mask, he wouldn't be himself if he didn't put his two cents into the discussion about terraforming Mars. One of Musk's ideas is to descend to the Martian poles. hydrogen bombs. A massive bombardment, in his opinion, would create a lot of thermal energy by melting the ice, and this would release carbon dioxide, which would create a greenhouse effect in the atmosphere, trapping heat.

The magnetic field around Mars will protect the marsonauts from cosmic rays and create a mild climate on the surface of the planet. But you definitely can't put a huge piece of liquid iron inside it. Therefore, experts offer another solution - insert w libration point L1 in the Mars-Sun system great generator, which will create a fairly strong magnetic field.

The concept was presented at the Planetary Science Vision 2050 workshop by Dr. Jim Green, director of the Planetary Science Division, NASA's planetary exploration division. Over time, the magnetic field would lead to an increase in atmospheric pressure and average temperatures. An increase of just 4°C would melt ice in the polar regions, releasing stored CO₂this will cause a powerful greenhouse effect. Water will flow there again. According to the creators, the real time for the implementation of the project is 2050.

In turn, the solution proposed last July by researchers at Harvard University does not promise to terraform the entire planet at once, but could be a phased method. Scientists came up with erection of domes made of thin layers of silica airgel, which would be transparent and at the same time provide protection from UV radiation and warm the surface.

During the simulation, it turned out that a thin layer of airgel, 2-3 cm, is enough to heat the surface by as much as 50 °C. If we choose the right places, then the temperature of the fragments of Mars will be increased to -10 ° C. It will still be low, but in a range that we can handle. Moreover, it would probably keep the water in these regions in a liquid state all year round, which, combined with constant access to sunlight, should be enough for the vegetation to carry out photosynthesis.

Ecological terraforming

If the idea of ​​recreating Mars to look like Earth sounds fantastic, then the potential terraforming of other cosmic bodies raises the level of fantastic to the nth degree.

Venus has already been mentioned. Less well known are the considerations terraforming the moon. Geoffrey A. Landis from NASA calculated in 2011 that creating an atmosphere around our satellite with a pressure of 0,07 atm from pure oxygen would require a supply of 200 billion tons of oxygen from somewhere. The researcher suggested that this could be done using oxygen reduction reactions from lunar rocks. The problem is that due to low gravity, he will quickly lose it. As far as water is concerned, earlier plans to bombard the lunar surface with comets may not work. It turns out that there is a lot of local H in the lunar soil₂0, especially around the South Pole.

Other possible candidates for terraforming - perhaps only partial - or paraterraforming, which consists in creating on alien space bodies closed habitats for humans (6) these are: Titan, Callisto, Ganymede, Europa and even Mercury, Saturn's moon Enceladus and the dwarf planet Ceres.

6. Artistic vision of partial terraforming

If we go further, to exoplanets, among which we increasingly come across worlds with great resemblance to the Earth, then we suddenly enter a completely new level of discussion. We can identify planets like ETP, BP and maybe even HP there at a distance, i.e. those that we do not have in the solar system. Then achieving such a world becomes a bigger problem than the technology and costs of terraforming.

Many planetary engineering proposals involve the use of genetically modified bacteria. Gary King, a Louisiana State University microbiologist who studies the most extreme organisms on Earth, notes that:

"Synthetic biology has given us a wonderful set of tools that we can use to create new types of organisms that are specifically tailored to the systems we want to plan."

The scientist outlines the prospects for terraforming, explaining:

"We want to study selected microbes, find genes that are responsible for survival and usefulness for terraforming (such as resistance to radiation and lack of water), and then apply this knowledge to genetically engineer specially designed microbes."

The scientist sees the biggest challenges in the ability to genetically select and adapt suitable microbes, believing that it could take "ten years or more" to overcome this obstacle. He also notes that the best thing would be to develop "not just one kind of microbe, but several that work together."

Instead of terraforming or in addition to terraforming the alien environment, experts have suggested that humans could adapt to these places through genetic engineering, biotechnology, and cybernetic enhancements.

Liza Nip of the MIT Media Lab Molecular Machines Team, said synthetic biology could allow scientists to genetically modify humans, plants, and bacteria to adapt organisms to conditions on another planet.

Martin J. Fogg, Carl Sagan fasting Robert Zubrin i Richard L.S. TyloI believe that making other worlds habitable - as a continuation of the life history of the transforming environment on Earth - is completely unacceptable. moral duty of humanity. They also indicate that our planet will eventually cease to be viable anyway. In the long run, you must consider the need to move.

Although proponents believe that there is nothing to do with the terraforming of barren planets. ethical issues, there are opinions that in any case it would be unethical to interfere with nature.

Given humanity's earlier handling of the Earth, it is best not to expose other planets to human activity. Christopher McKay argues that terraforming is ethically correct only when we are absolutely sure that the alien planet is not hiding native life. And even if we manage to find it, we should not try to transform it for our own use, but act in such a way that adapt to this alien life. By no means the other way around.

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