Mars is so cold, how can people live?

Some people think that the environment of Mars can be transformed into the appearance of the earth, mainly as an immigrant place for future population explosion. There are several ways:

1. Add appropriate gases (including greenhouse gases and gases suitable for biological existence) into the atmosphere to increase the surface temperature and pressure, mainly for liquid water, followed by plants and animals.

2. Set up a huge reflecting (or refracting) mirror group in space to reflect sunlight to the surface of Mars.

3. Melt a lot of underground frozen soil, and then lead the water to the surface. Although it will freeze at first, with the progress of the project, the ice will melt and form a hydrosphere.

4. Cultivate dark algae on the ice surface (including the poles) to accelerate melting.

5. Spread sand-fixing fungi and plants to prevent sandstorms, then generate soil and expand living areas.

When the underground melts, although the weight of the upper frozen soil will squeeze the melted liquid water to the surface, the stratum will sink, the formed ice will increase the albedo of the surface, and the water sublimated into the atmosphere will change the climate. These factors should be taken into account.

But of course, there is another problem, that is, radiation from space. Although mirrors can be used for treatment in space, they are very fragile. The most fundamental way is to go to the core and start the magnetic field of Mars to resist the solar wind and cosmic rays. But this requires a lot of energy and the required technology needs to be strengthened. In addition, the cause of geomagnetism is still unknown.

However, before the construction, human beings should look at everything on this planet completely and carefully, set up protected areas and development restrictions, because as long as the construction starts, it will cause great damage to the long-term preserved geological data, and it will be too late to regret it.

So I personally think that it is a long journey for human beings to enter Mars. If Martians really exist, they may even have to fight for colonization!