Our reporter Fu Yifei

　　On July 17, the Long March 5 Yaosi carrier rocket was vertically transported to the launch area, which means that my country’s planetary exploration project "Tianwen-1" mission will be implemented soon.

　　Although this is our country's first mission to explore Mars, it has already triggered endless reveries among Mars fans-can we build a hotel on Mars in the future? Can mining on Mars? What scientific experiments can be carried out on Mars? What's more, the most realistic question in the science fiction world is raised: what kind of food should we grow when we emigrate to Mars?

　　"In the long run, the development of unique human civilizations on Mars, including various agricultural civilizations, industrial civilizations, and technological civilizations can be expected." Zheng Yongchun, a researcher at the National Astronomical Observatory of the Chinese Academy of Sciences, told a reporter from Science and Technology Daily.

　　So, how should humans transform and build this red planet if they want to colonize Mars? Listen to what the experts say.

　　Farming on Mars is much more than just solving the problem of eating.

　　In the science fiction movie "The Martian", the protagonist Mark survives alone on Mars by growing potatoes. Zheng Yongchun said that if mankind wants to immigrate to Mars, building an agricultural civilization is definitely the first step, but its role is far more than just solving the problem of eating.

　　If the agricultural technology in daily life is mainly dedicated to improving agricultural yield, crop quality, and diversification of agricultural products, on Mars, we must open up a new field of agricultural research, with the primary purpose of transforming the environment. "In addition to providing food, we need plants to supply oxygen, purify water, etc., to provide humans with the most basic living conditions." Zheng Yongchun said.

　　He believes that by then, some low-grade plants and even microorganisms, such as bacteria and algae, need to go ahead. Let them adapt to the environment on Mars, absorb carbon dioxide, release oxygen, and then produce organic matter, transform the soil of Mars, make the surface environment of Mars more and more like the earth, and more friendly to life. This process requires scientists to carry out a large number of forward-looking studies on the earth to screen out microorganisms, plants and crops that have the ability to adapt to the Martian environment, as the "first march" for immigration to Mars. Nowadays, scientific research institutions at home and abroad are already carrying out relevant research work. In 2016, the National Aeronautics and Space Administration (NASA) Kennedy Space Center and Florida Institute of Technology jointly launched the "Mars Garden" project, with the purpose of screening plants that can adapt to the Martian environment. Currently the project has entered the testing phase.

　　However, there are many factors that affect plant growth, including moisture, heat, light, fertilizer, and gravitational conditions. Whether the plants selected on the earth can grow normally on Mars, whether they will mutate, lack biodiversity, and whether the ecosystem can remain stable, there are too many questions to study. In addition, there are many uncertainties in this work. For example, how will the "first march" evolve after arriving on Mars, and will it be the first to "occupy" Mars? These all require in-depth research.

　Build a semi-basement in an area near water and good sunlight

　　When human beings arrive on Mars, they are bound to face housing problems, which requires the construction of a Mars base.

　　Pang Zhihao, the chief science communication expert of national space exploration technology, said that the construction of a Mars base is a long-term vision for mankind. It takes a long process from the initial construction of a temporary base to the realization of medium-term residence, and then to the transformation of Mars to build a permanent base. The ultimate goal is to emigrate to Mars.

　　In recent years, countries around the world have been enthusiastic about building lunar bases, and many countries have formulated plans or proposed plans. Compared to the moon, some conditions on Mars are more suitable for base construction. For example, the rotation period of Mars is about 24 hours and 40 minutes, which is similar to that of Earth. At the same time, there is water on Mars, a thin atmosphere, and four seasons. These environmental conditions are very similar to those of the earth, which gives people the hope of colonizing Mars.

　　Pang Zhihao introduced that to build a temporary base on Mars, before the astronauts arrive on Mars, an unmanned cargo spacecraft can be used to send living cabins and non-regenerative life support systems that meet basic needs to Mars. The construction of a medium-term base on Mars requires at least the use of materialized regenerative life support technology to achieve more efficient recycling of materials. To build a permanent base on Mars, a biological regenerative life support system is needed to achieve 100% recycling of materials.

　　At the same time, the Mars base must have a power system, such as a small nuclear power plant; there must also be a Mars rover, after all, astronauts cannot stay in the house all the time and need to expand the scope of their activities.

　　In addition, Pang Zhihao believes that the location of the Mars base is very important, and it is best to be close to a place with water and full of sunshine. In order to withstand storms and radiation, the early bases should be underground or semi-underground.

　　During the construction of the Mars base, it is obviously unrealistic to rely solely on the transportation of supplies from the earth. Zheng Yongchun believes that taking local materials is an important principle. He said that sand, dust, soil, hematite, and even salt minerals in dry lakes that are easily available on the surface of Mars are all targets we can use.

　　Do scientific research on Mars and study Mars as another earth

　　When mankind landed on Mars, apart from growing food and engineering, it should also do other things. Someone asked, can mineral resources be discovered and shipped back?

　　Zheng Yongchun said that from the current analysis of technical capabilities, even if the gold bricks are everywhere on Mars, it is not worth taking back, because the cost is far greater than its value.

　　This is not an exaggeration. Half a century ago, the American Apollo project brought back 382 kilograms of rock samples from the moon. Some people calculated that the cost of these stones was equivalent to more than 30 times that of diamonds of the same weight. This is true for the moon, which is more than 300,000 kilometers away from the earth, not to mention Mars, which is 50 million kilometers away from the earth.

　　As mentioned earlier, most Martian resources are only valuable when used in situ. As long as the weight of materials transported from the earth can be reduced, the development of expensive resources is also cost-effective.

　　Although the road to mining is unworkable, humans can engage in scientific research on Mars, which is also one of the important purposes of human exploration of the universe.

　　At present, human beings have carried out a lot of scientific research with the help of the moon, mainly including several aspects, such as studying the earth from the moon, looking at space from the moon, and studying the moon itself.

　　However, Zheng Yongchun believes that scientific research on Mars is different.

　　First of all, Mars is too far away from the earth, and there is no advantage in observing the earth from there. Perhaps the greatest significance is to soothe the soul and entrust homesickness.

　　Astronomical observations on Mars are of little significance. After all, near-Earth space and the moon have provided good astronomical observation platforms, and it is not easy to transport large telescopes to Mars.

　　Zheng Yongchun said that the most valuable scientific research on Mars is to study Mars as another earth. He said that now humans have studied the earth's surface, depths, atmosphere, and biosphere almost all the time, but humans' understanding of the earth is still not deep enough. The reason is that they lack a suitable reference object and have not jumped out of the earth to see the earth. If there is a planet that is very similar to the earth, but the final destiny is different, then conducting comparative studies based on this will give a lot of enlightenment.

　　Mars is like the twin brother of the earth. Zheng Yongchun said, for example, there used to be an ocean on Mars, but now there is no one. For scientists, its coastline, ocean sediments, water vapor cycle, etc. can all be used as research topics.

　　Another example is that weather forecasts are always inaccurate, because various influencing factors such as vegetation, atmosphere, and water surface on the earth make weather forecast models very complicated. There are also dust storms, snow, and various meteorological phenomena on Mars, but its meteorological model is much simpler than that of the Earth. Comparing the two, scientists can find many new research topics and have a lot to do.

　　In addition, there are mountains, valleys, volcanoes, glaciers, and cold and dry regions on Mars... "If the various research institutes of the Chinese Academy of Sciences are moved to Mars, many disciplines can find research themes there and gain new research perspectives." Zheng Yongchun said.