What do you need to grow a garden? Abundant sunlight alternating with gentle showers requires good, fertile soil to provide essential minerals as well as busy bees and butterflies to pollinate the plants. But imagine that you have no fertile soil, no showers, no bees and butterflies. And the sun was too harsh and not in direct sunlight, which caused sub-zero temperatures.
Can plants grow in such an environment? So, in what environment can you grow it? This is a question that should be addressed if (or when) the colonists of the Moon (and Mars) continue human exploration of neighboring planets. Now a new study, Journal of Communication BiologyStarted to provide answers.
The researchers behind the study have grown fast-growing plants. Arabidopsis From samples of lunar topsoil (soil) taken by the Apollo astronauts from three different places on the moon.
This isn’t the first time doing it. an attempt was made But growing plants in lunar topsoil shows for the first time why they don’t thrive.
The lunar topsoil is very different from the terrestrial soil. First of all, it does not contain the organic matter (worms, bacteria, decaying plant matter) that is characteristic of Earth’s soil. It also has no inherent moisture content.
However, topsoil has the potential to grow plants, assuming that it is composed of the same minerals as soil and that growing plants in the lunar habitat ameliorates the lack of water, sunlight and air.
Research has shown that this is indeed the case. seeds of A. Taliana The Apollo material also germinated at the same rate as in land soil. However, while plants on land soil continued to develop rhizomes and produce leaves, Apollo seedlings were stunted and had poor root growth.
The main objective of the study was to examine plants at the genetic level. This allowed scientists to recognize certain environmental factors that trigger the strongest genetic response to stress. They found that the majority of the stress response in all Apollo seedlings came from highly reactive salts, metals, and oxygen in lunar samples (the last two being uncommon in terrestrial soils).
The three Apollo samples were affected to different degrees and the Apollo 11 sample had the slowest growth rate. Because the chemical and mineralogical compositions of the three Apollo soils were quite similar to each other and even to land samples, the researchers suspected that nutrients were not the only force acting.
The terrestrial soil called JSC-1A was not ordinary soil. It was a mixture of minerals specially prepared to simulate the lunar surface and contained no organic matter.
The starting material was basalt, as in the lunar topsoil. In the terrestrial version, “glassy mass” – small fragments of minerals mixed with molten glass – abundant in the lunar topsoil.
The scientists recognized that clumps were one of the potential causes of undergrowth by seedlings on Apollo soil compared to terrestrial soils and one of the potential causes for differences in growth patterns between the three lunar samples.
Agglomerates are a common feature of the lunar surface. Ironically, it is formed by a process called “gardening the moon.” This is how topsoil changes through impact on the lunar surface by tiny meteorites, also known as cosmic radiation, solar wind, and cosmic weathering.
Because there is no atmosphere to slow down the small meteorites hitting the surface, they collide at high speed, melting at the point of impact and then causing a rapid cooling (quenching).
Gradually, small lumps of minerals combine into glass and build up. They also contain small particles of ferrous metal (nanophase iron) formed by spatial weathering processes.
The main difference between the glass chunks in the Apollo sample and the natural volcanic glass in the land sample is this iron. This was also the most likely cause of metal-related stress recognized in the genetic profile of plants.
Therefore, due to the presence of aggregates in the lunar matrix, Apollo seedlings suffer compared to seedlings grown on JSC-1A, specifically Apollo-11. The amount of aggregates in the lunar topsoil sample depends on the amount of time the material has been exposed to the surface, indicating that “maturity“Lunar soil.
Very mature soils have been on the surface for a long time. They are found where topsoil has been undisturbed by more recent impact events that have created the crater, while immature soils (below the surface) occur around fresh craters and on steep crater slopes.
The three Apollo samples have different maturities, with the Apollo 11 material being the most mature. It contained the most nanophase iron and exhibited the highest metal-related stress markers in the genetic profile.
The importance of young soil
The study concluded that more mature topsoil was a less effective substrate for growing seedlings than less mature soils. This is an important conclusion as it shows that plants can grow in lunar habitats using topsoil as a resource. However, the location of the habitat should be determined by the maturity of the soil.
And finally, it occurred to me that the findings of this study could also be applied to some of the poorest parts of our world. I don’t want to repeat the old adage, “Why spend all this money on space research if it could be better spent on schools and hospitals?” That will be the subject of another article.
But are there any technological developments arising from this research that are applicable to Earth? What have we learned about stress-related genetic changes to develop drought-tolerant crops? Or is it a plant that can tolerate higher levels of metal?
If growing plants on the moon could help gardens grow greener on Earth, it would be a great achievement.