To build a habitable planet from scratch is definitely not fantastic. On the one hand, curiosity makes us have some desire to conquer the unknown. Humans have never stopped exploring space since ancient times; on the other hand, the earth is facing many global threats, such as climate change, overpopulation, and potential epidemics. Wait, in order to deal with these threats, it is always good to prepare a backup plan.
So, what conditions should be met if a habitable planet is to be built?
First of all, to find a suitable place in space, the planet needs to be in the habitable zone. This means that the planet must have a temperature suitable for life and maintain a proper distance from the star. Because if the planet is too close to the star, we will be scorched by the heat of the star, and if it is too far away, we will be frozen in a low temperature environment.
In addition, there must be a large amount of liquid water on the planet, as well as an atmosphere containing breathable gas, stable gravity similar to the earth, and proper day and night cycles. Only by meeting these prerequisites, can the plan to build a habitable planet from scratch be realized.
At present, there are two main ideas for building "man-made habitable planets": one is to make a planetary replica that is almost indistinguishable from other planets in the solar system; the other is to build a huge satellite in space, just like "Star Wars" "Death Star Space Station in ".
Let me talk about Option 1: Build a complete planet.
Rocky planets like the Earth are formed by the accumulation of remnants released when the sun was born. Over millions of years, these remnant particles have gathered together bit by bit, piece by piece, until a habitable one is formed. planet. Therefore, we can try to imitate the process of nature forming planets, but at a faster pace.
We can build an advanced nuclear fusion facility near the sun, where we can obtain the heavier materials needed to build new terrestrial planets. The denser elements, such as osmium, iridium, and platinum, will be a good choice for building replica planets. These heavier elements can be layered together and then cooled naturally.
Currently, the only way humans know to obtain these elements is the thermonuclear explosion of supernovae. However, even if this method can be used to speed up the planetary formation process, it would take thousands of years to build a planet.
The first option is difficult to achieve, we might as well explore the second option: to form a space station.
If steel is mainly used as a building material, it will need about 1,000 trillion tons of steel. At present, humans can only produce about 1.8 billion tons of steel each year, which means it will take more than 800,000 years to meet its demand for steel. To obtain the raw materials for the construction of a planetary space station, the only workaround is to obtain it from space. To this end, we may need to mine asteroids or even the moon.
Assuming that we have overcome the logistical challenges of sourcing raw materials to some extent, then we need to use advanced robots that can work in microgravity to build a habitable spherical object. Only in this way can the earth-like gravity be obtained, otherwise the human body may become very bad in the state of weightlessness.
Even though it is much easier to build a planet-like spherical space station than to build a huge terrestrial planet, there may be inherent flaws-lack of stability. In order to maintain its stable operation, we need to carry out a lot of active maintenance, and it will take several centuries for our technology to reach this level of maintenance.
In addition to the above two ideas, there is a more feasible option-terraforming planets or satellites to make them suitable for human habitation. For example, we can carry out a nuclear explosion on Mars to warm the atmosphere to the level we need, and then find a technology that can preserve the Martian atmosphere so that it can maintain a suitable temperature like the earth. Some researchers believe that this idea may become a reality within a few decades.
Whether it is building a complete planet or forming a space station, it is unlikely to be achieved with the current level of technology. However, terraforming the existing planet is a more feasible solution. For humans, this is already an incredible miracle.
