The first choice for human beings to move into space

(2) rotation cycle; The angle between the equatorial plane and the orbital plane; low

(3) Mars is the fourth closest planet to the sun in the solar system, and its distance from the sun is far from the earth, so its temperature condition is worse than that of the earth; this

In addition, the mass and volume of Mars are smaller than that of the Earth, so it may attract less atmosphere and its atmospheric density is smaller than that of the Earth. Not on Mars either.

There is water. We think that temperature, atmosphere and water are necessary conditions for the existence of life, but Mars does not have these three aspects, so we put them on Mars.

There is no life.