Mars has a rotation period of 24:37, almost the same as that of the Earth. In addition, its gravity is one-third that of the Earth. The tilt of the rotation axis is 25.19 degrees. Earth's is 23 degrees. From this point of view, it may be closer to Earth than to Venus, but it is a delicate point. In terms of exploration and migration, Mars is probably the better candidate.
Let's get down to business. First, how to terraform Mars. Perhaps, artificially created methane will be distributed to the Martian atmosphere. Then the concentration of greenhouse gases will increase and the temperature will rise. This would increase carbon dioxide at the poles, which would lead to a runaway increase in greenhouse gases. But they say it will take about 100,000 years to complete this. Therefore, it is illogical.
Furthermore, even if water were carried, it would be constantly exposed to the solar wind due to the lack of a magnetic field. Hydrogen, for example, would also be scattered in space. However, a way around this would be to create a huge artificial magnetic field at the L1 Lagrangian point on Mars, which would prevent the solar wind. But there is still a problem. How to recall volatile elements and greenhouse gases deep underground on Mars? Perhaps by placing a giant sorretta over Mars and directing sunlight onto the ground, a dense, volatile atmosphere would cover the planet.
Mars would then become habitable. But we need to produce oxygen. In other words, we can create plants. Plant plant seeds and have them produce oxygen, and at the same time, build the planet so that life forms can be established on it.
Terraforming Mars
Moderator: Franck