The moon is not suitable for life. The temperature of the moon at night is below -200°C, and it exceeds 120°C during the day. There is no air, high-energy particles and solar wind. These are all factors that are not suitable for life.
In 2013, NASA announced plans to grow vegetables on the moon in 2015, but no country has ever grown anything on the moon.
In 2015, the country took out the precious 3 kg payload of Chang’e-4 and solicited proposals from all over the world. In the end, the “Science Popularization Payload of the Lunar Mini Ecosphere” proposed by our team stood out from 257 proposals. We are trying to build an ecosystem of producers, consumers, and microbes on the moon for cultivation experiments.
Chang’e-4 was completed in 2013, and its location and space were all arranged. We can only do this experiment in a small space of 200 mm x 200 mm x 200 mm with a weight of only 3 kg.
To conduct biological experiments on the moon, the temperature needs to be controlled between -10°C and 40°C. If it is lower than -10°C or higher than 40°C, the seeds will die. Everything grows by the sun, and a day on the moon is 14×24 hours, and the sun is very abundant. But our pots are small, and if too much sunlight gets in, the temperature becomes difficult to control. After calculation, if it is necessary to control the temperature and meet the conditions of photosynthesis, an 8mm-diameter sunlight entry is required. So we left a little bit of leeway and used a 10mm diameter light pipe to bring sunlight into the jar.
Some people may say, just use incandescent light or artificial light directly. But we believe that if we finally go to the moon to do experiments, we must use the original resources of the moon.
Water is the source of life, and there is no liquid water on the moon. We need to precisely control the water we carry: not too much, because nothing can grow in the vast ocean; not too little, to meet the needs of plants to germinate. After precise calculation, we must bring 18 grams of water to the moon. Water is also the switch of our experiment, and the watering experiment starts immediately.
It takes several days or even dozens of days for life to have observable changes in phenomena, but our time is only 9 days at most. Why is it 9 days? Because one day of the moon is 14 days, but it is impossible for Chang’e-4 to land on the first day of the moon’s day, why? Because the temperature is too low and there is too little sunlight, we have to wait for the temperature on the lunar surface to be more suitable before landing.
Who is the “protagonist” of the lunar biological experiment
The choice of species is also important. Our microbiome must include plants, animals and microorganisms. Regarding the selection of plants, the first thing to consider is what the astronauts will eat, wear, and use on the moon in the future. Therefore, the selected species must be the necessities of life; these species must also have the ability to resist high temperature and low temperature; in addition, different seeds The temperature required for germination is different. For example, cotton only germinates at high temperatures. And we don’t know when the lander will land and when the experiment will be done, so the germination temperature of the selected seeds should be staggered.
The choice of animals is also very particular. We selected several animals from hundreds of animals, first of all, the tortoise, because the tortoise has a shell, so it can protect itself when launching, and the tortoise does not like to exercise. In addition, the tortoise also has a good meaning, that is, the tortoise and the hare race: when the little jade rabbit stops on the moon, let the tortoise climb up. However, when the tortoise is dormant, it takes less than 20 days to absorb the oxygen in the container. The lander will take 3 months to reach the moon, so the tortoise will die before reaching the moon, and we cannot use it for experiments.
We chose a biological model animal – Drosophila.
Finally, we selected six species of potato, rapeseed, cotton, Arabidopsis, fruit fly and yeast to conduct experiments on the moon to form a miniature ecosystem.
The tank we finally designed for the “biological experiment on the moon” is 198 mm high, 173 mm in diameter, and weighs 2.608 kg. Why only 2.608 kg? Because we can’t take the battery to the moon, and we don’t have time to do other designs, the remaining very precious 300 grams are useless.
The first green leaf on the moon is born
At 10:26 on January 3, 2019, Chang’e-4 landed on the moon. Since Chang’e-4 has to do a lot of experiments and tests, we were not told that experiments could be done until 23:18 on the same day, and we immediately started powering up and taking pictures, both of which were triggered at the same time.
Everyone breathed a sigh of relief after seeing the first photo taken, because there was no lush greenery or dead branches and leaves that many experts worried about, and the photos we took were exactly the same as those on the ground. At that time, the temperature outside had exceeded 100°C, but it was only 30.6°C inside the device. So as long as the seeds are not dead and the water can be released, the experiment may be successful.
Half an hour later, we received an order that the water could be released, so we drained 18 grams of water at once.
Then the sunlight from the moon also came in. There is light, water, air, and the right temperature. As long as the seeds are not damaged, our experiment may be successful. There is a small green spot in the photo taken on January 4th, 2019, but at that time we dare not say that the seeds had germinated, because we were worried that the green spot might be a screw that fell and became moldy, or a rotten seed.
On January 5, 2019, the seeds grew a little bit, and we were a little excited at this time.
By January 7th, we saw that the seed had grown a leaf, and we knew the experiment was a success. At around 8:00 p.m. on January 7, 2019, the director of the National Space Administration brought a group of people to our work station to check. After everyone confirmed that the seeds had germinated, they released the photos to the world.
We also did a simultaneous experiment on the ground, which only saw the germination point on January 7, so the seeds germinated almost three days earlier on the moon than on the earth. In the lunar environment, some changes have taken place in the morphology and growth mechanism of leaves.
After the experiment was successful, on January 13, 2019, CCTV released the news to the world, causing an international sensation. Both Nature and Science called the experiment a “first ever”. The first lunar biological experiment of mankind was realized by the Chinese.
This experiment has been successful, and everyone must have a lot of imagination about the next step of lunar exploration and the next step of human beings living outside the earth.
For example, we can build gardens on the moon in the future, allowing astronauts to breathe oxygen produced by photosynthesis. We can also build food factories and farms on the moon, eat the food we grow on the moon, and eventually build our moon base.
With the development of science and technology, human beings are constantly expanding the extraterrestrial living space. Is it possible to have moon babies in this century? We can work together and dream together!