Can humans migrate to Mars?

As early as more than a century ago, in science fiction, humans began to walk on Mars, but until today this is only an idea. But many people firmly believe that the question is not whether humans can land on Mars, but when and how to get there. So far, no one knows exactly how to reach Mars in the most convenient and labor-saving way. Some people estimate that it will cost 60 billion dollars or more for humans to land on Mars. However, Robert Zublin, president of the Mars Society, thinks that the figure should be $30 billion to $40 billion, which is equivalent to the cost of the Apollo moon landing program. Zublin published a book called Migration to Mars, which outlined the grand blueprint for human settlement on Mars.

Why do humans always yearn for Mars? Because according to the current observation, Mars is the most likely place to become the second home of mankind. Although the temperature on Mars is minus 200℃, the environment on Mars is the most similar to that on Earth among all the planets in the solar system. Mars is about half the diameter of the earth, with one third of its gravity and one percent of its atmospheric concentration. Most importantly, the probe found water at the frozen poles and below the surface of Mars. Every two years, Mars will approach the Earth. This summer, Mars came to a place 55.76 million kilometers away from the Earth, which is the closest to the Earth in 60,000 years.

Zublin said: "People really want to know whether there is life outside the earth, and Mars may be the key to solve this problem. On Mars, even if only microorganisms in the original state can be found, it means that human-like life does not only exist on the earth. "

Louis Friedman, president of the Planetary Society, said that the basic question that human beings want to answer is, where do people come from? Where are you going? "The most attractive thing about Mars is that it may help us understand the origin and destination of life." "Moreover, Mars is the only place where we know that human beings have the opportunity to immigrate, which will prove that they will not stay on the earth forever; If we (a) can immigrate to Mars, then the earth may (b) be our only home, and we will have to re-examine the relationship between human beings and the earth. " The second paragraph uses a variety of interpretation methods, please list two and analyze their functions.