Fifty-two years ago, the United States was able to send a man to the moon, but it has not yet restored the Martian soil. Are you afraid of unknown life?

Before 1950s, human beings were still in the groping stage in the field of space exploration, and there was no real progress. It was not until 1957 10.04 that the first artificial satellite was launched by the Soviet satellite launch vehicle. If someone said at that time that man could land on the moon in a few years, take samples on the moon and return to the earth safely, most people would think it was impossible.

However, from 196 1, the United States, which once lagged behind the Soviet Union in space exploration, began to implement its own manned Apollo program. In just eight years, Apollo spacecraft 1 1 in 1969 was successfully launched on the Saturn V launch vehicle, carrying three astronauts, Armstrong, Aldrin and Collins. Among them, Armstrong and Aldrin successfully landed on the moon, which has plagued mankind for 5000 years, and brought back 2 1.55 kg of lunar rock samples collected on it when they left the moon and returned to Earth.

This moon rock of more than 20 kilograms is extremely precious, because it is the first time that human beings have come into contact with rocks on the moon. Even if someone has seen a meteorite before, it is impossible to confirm whether it is from the moon. At that time, the United States gave China 1 g lunar soil, while Academician Ouyang Ziyuan only took 0.5 g for research and published 14 high-quality scientific research papers.

Compared with the moon, which is only 380 thousand kilometers away from the earth on average, Mars, which is 400 million kilometers away from the earth, is more mysterious and valuable for research. Humans even regard it as the most suitable planet for immigrants. Moreover, as early as 1976, a probe landed on Mars, but the sampling return has not been realized until today. What is the reason?

Mars exploration in the United States is still very early. Mariner IV, the first Mars probe, was launched as early as 1964. It sent back the first photo of the surface of Mars, but it didn't land on Mars.

The first probe to successfully land on Mars was Viking- 1 Mars probe in the United States, and the time was 1976.

Subsequently, the United States launched many Mars probes, but all of them were satellites flying around Mars. It was not until 2004 that Opportunity and Spirit landed on the surface of Mars. Just last July, the American rover "Perseverance" also successfully launched and landed on the surface of Mars, and collected samples of Mars, but these samples of Mars could not be brought back to Earth immediately.

In other words, the rover Perseverance can only temporarily collect samples and save them. It is expected that the United States will cooperate with the European Space Agency to bring them back to Earth in 20031year. Once these samples are brought back to Earth, scientists will be able to solve the mystery of whether there is life on Mars.

However, even the time point of 203 1 is only an optimistic prediction, and the time to really bring it back to Earth may be delayed. So why hasn't the United States achieved the return of Mars sampling?

On this issue, some people say that they are afraid that unknown microorganisms on Mars will leak to the earth. That's not the reason. Why?

Scientists speculate that a long time ago, Mars had a suitable climate, abundant water resources and even the probability of life. Of course, this kind of life is not necessarily a civilized alien, but a simple life like some bacteria.

In 2008, the American Phoenix Mars probe landed on the surface of Mars with a professional Martian soil analysis instrument, but you should know that this operation was not attended by anyone and its volume was limited, so the results obtained could not thoroughly study the Martian soil.

Experts say that the Phoenix Mars probe can only distinguish organic matter in Martian soil, but not protein, DNA and other things. In other words, there is a certain probability that there are unknown microorganisms in the Martian soil brought back. Of course, this problem is easy to solve. Because the space sampling return and related research processes are carried out under extremely strict safety measures, even if they exist, there is no need to worry about leaking into the earth's environment. On the contrary, scientists on earth are particularly eager to get soil samples on the surface of Mars as soon as possible. So as to completely uncover the mystery of whether there is life on Mars.

First of all, we can't directly compare the experience of exploring the moon with that of exploring Mars, because the distance from the earth to the moon is only 380,000 kilometers, and the distance from the earth to Mars is 55 million to 400 million kilometers, so the difficulty of exploring Mars is much greater than that of exploring the moon, mainly in the following aspects:

At 1, the gravity of Mars is twice that of the moon, and the escape speed of the moon is 2.4km/s, while that of Mars is 5.02 km/s. Therefore, if the Mars probe wants to leave the surface of Mars loaded with Martian soil, it needs a lot of fuel and high equipment weight.

2. The distance between the Earth and Mars is too far, so it is necessary to prepare a lot of fuel. On the premise of a certain rocket thrust, the weight of the Mars probe will be smaller, which seems to contradict the first higher equipment requirements.

Some experts suggest using local materials on the surface of Mars to produce fuel, but it is also very difficult. Not for a short time.

In the final analysis, because it is twice as difficult to sample from Mars as it is to explore the moon, we can't simply compare the speed of exploring the moon with Mars.

Since man landed on the moon for 50 years, science and technology have changed with each passing day. The "Tenacity" Mars probe, which invested 2.7 billion US dollars in 2020, only temporarily collected and preserved the soil on the surface of Mars. The detector that can really bring back samples is still under development, and it will take 10 years at the earliest.

At the same time, China's Tianwen-1 Mars probe is carrying out scientific research activities on the surface of Mars. Chief designer Tian Wen No.1 said that our country is also conducting preliminary technical research on Mars sampling and return. I believe that in the near future, China can also realize the return of Mars sampling.