Why doesn't the United States develop the moon first and focus on Mars?

Why didn't the United States develop the moon first? As soon as I saw this problem, I think many people would think that the American landing on the moon was a scam. The American landing on the moon is actually not a scam. The United States has reason to explore Mars without developing the moon.

Compared with Mars, the moon has some advantages, but not all. The advantages of the moon are closer to the earth, smaller surface acceleration and richer mineral resources, but the moon is not without its shortcomings. First of all, the moon has no atmosphere, so the temperature difference between day and night is very large, reaching more than 300 degrees Celsius. Besides, there is no water on the moon. If the moon is really developed, the cost will be high.

After talking about the moon, let's talk about Mars. We say that Mars is better than the moon. One is that the atmosphere of Mars is thin, which will make the temperature difference between day and night of Mars not too big, and the temperature in most parts of Mars will not be too high. Secondly, the water resources on Mars are not liquid water, but there are a large number of ice sheets at the two poles of Mars, and there may be liquid lakes under the Antarctic ice sheet. Third, Mars is rich in resources. There is a lot of dry ice on Mars, which can be used to synthesize methane fuel. In addition, the gravity acceleration of Mars is actually only 38% of that of the Earth, which may be more suitable for migration than the 1/6 of the Moon.

However, the biggest problem of emigrating to Mars is that Mars is too far away from the Earth. The nearest distance is 55 million kilometers. It takes at least half a year to go from Earth orbit to Mars orbit. It is really difficult to reach Mars, but for those who dare to challenge, sooner or later they will land on Mars and even colonize it. Of course, there is no reason for the United States to give up the closer moon, or to have both. The United States also intends to return to the moon in the future. The plan to land on the moon is now shelved because people have already landed on the moon. Therefore, more energy is being devoted to the development of Mars.

In fact, today's human space development has become a commercial investment, only losing money without making money, but it is also an investment that has to be made, because it is related to the future development of mankind. After all, in the long run, the environment of the earth will be unsuitable for human habitation sooner or later. If human beings don't want to be buried by the earth, they must invest huge sums of money to develop mature space technology.

Among the eight planets in the solar system, except the earth, only Mars is suitable for human habitation, and Mars is not too far away from the earth. So after landing on the moon, the United States turned its attention to Mars, and in theory, because the environment of Mars allows humans to land, this means that Mars may be transformed by humans, so landing on Mars is something that the United States must do.