Of course, they didn’t do it just to see if they could. Researchers – two gardeners and a geologist from the University of Florida – tested the viability of plants in lunar soil to hope that they would be useful for future landings on the moon or Mars. Space-grown plants could potentially offer fresh produce, oxygen and water recycling to astronauts conducting these missions. If life on Mars indeed in our future, space agriculture will have to step up its game.
Lunar soil or regolith is a dusty by-product of the effects of micrometeorites on the moon’s surface. In samples obtained during the Apollo missions, scientists planted seeds of Arabidopsis, a small flowering plant often used in biological experiments. The seeds germinate within a week, but then the confidence in their longevity decreases.
“Our results show that growth is a challenge,” he wrote study, which was published in the journal Communications Biology this week. Plants grow slower and more unstable in regolith than in a produced soil imitation called JSC-1A; their leaves also unfolded longer. When researchers removed most of the regolith seedlings from their containers, they found that the root system was short, indicating slow growth. This was not the case with JSC-1A seedlings, whose root systems seemed generally healthy.
Regolith plants have also revealed their stress through genetic activity. Through transcriptome analysis, the researchers found that regolith plants activated genes involved in nutrient metabolism, phosphate starvation and aluminum toxicity.
Given that the seedlings have had such a difficult time settling in regolith, it does not appear that NASA will soon open a lunar greenhouse. The possibility of growing extraterrestrial products is even less likely, as the production of fruits and vegetables requires significant amounts of energy and other resources that these plants simply did not have. But this does not mean that any of these things are impossible – it may just take a little “soil optimization”, as the authors of the study optimistically point out.