For the first time, scientists were able to grow plants on samples of lunar soil brought back by Apollo 17 50 years ago. The work, led by the University of California, is an important step towards humanity being able to produce its own food in space, whether on the Moon or Mars.
The new study focused on assessing whether future astronauts who will live on the Moon will be able to grow vegetables in greenhouses using the resource available on the lunar surface: regolith. Samples of this material were brought to Earth between the 1960s and 1970s by NASA’s Apollo missions.
However, regolith is an unfriendly material. It is made up of tiny, dry and extremely fine grains of sand, with minerals and ions not found on Earth. Also, it has no organic material, as nothing, as far as is known, has decomposed on our natural satellite.
To grow the plants in this material, the researchers needed to add some nutrients and water. It worked—at least in part. “After two days, we were surprised to see that all the seeds had germinated,” said astrobiologist Anna-Lisa Paul, the study’s lead author.
The researchers were given a limited amount of regolith. Each sample contained about a gram of soil brought in by the Apollo 11, 12 and 17 missions. To control the study, they planted seeds in simulated lunar soil made of volcanic ash — material known to scientists as JSC-1A.
Planting in lunar soil
Working with the JSC-1A helped the team develop a diluted nutrient solution for growing the seeds. They used trays with 48 holes and, in three of them, they placed seeds with the lunar regolith plus the nutrient solution.
In another four, they placed the seeds with the simulated regolith plus the solution. The same setup was used on three other trays to improve experiment statistics. Then these dishes were moved to terrariums with ventilation and light.
The boxes were used to simulate the flow of air inside a laboratory on the surface of the Moon. The seeds in question are from the thale agaron (Arabidopsis thaliana) — known for their rapid growth. When they sprouted, they still consumed the nutrients stored in the seeds, without needing the soil.
After a week, when the nutrient stores were depleted, differences began to emerge. Compared to seedlings grown in simulated regolith, those grown in lunar material took longer to develop broad leaves, as well as being smaller and some deeply stunted.
Then the researchers performed genetic tests on each of the plants to assess what metabolic tools they were using to adapt to the new soil. And they found that the seedlings were stressed: “they were working hard to stay healthy,” Paul added.
For the authors of the work, it is a matter of time before we can grow plants on lunar soil. “We here on Earth are getting very savvy about how to grow plants in increasingly salty and drier environments,” said Robert Ferl, co-author of the study.
NASA has already done some research on lunar regolith, but nothing like the work of Paul and Ferl. By growing food plants in space, the burden of future manned missions to the Moon or beyond will be less, as there will be no need to carry as much food. In addition, the presence of vegetation has positive effects on the mental health of the crew.
For some years now, the cultivation of plants aboard the International Space Station (ISS) has been a reality. The crew mainly evaluate the ability to grow some plants on Mars or aboard spacecraft during the long space trips to the planet.
The authors of the work have no doubt: space agriculture will be in the future; and research has just introduced a part of the Moon to biology. “To me, this is so symbolic. When we leave Earth, we will take plants with us,” Paul concluded.
The research was published in the journal Communications Biology.
Source: Communications Biology, Via Wired