Scientists at the University of Florida have successfully cultivated a plant in lunar soil for the first time. The achievement could have significant implications for future long-duration space missions in which astronauts will need to have access to their own food sources.
To conduct the experiment, the scientists persuaded NASA to lend it samples of lunar regolith collected from different locations on the moon during three Apollo missions that took place five decades ago.
They then placed seeds of the hardy Arabidopsis plant in tiny samples of nutrient-poor lunar regolith and waited to see if anything happened.
To the scientists’ delight, green shoots started to appear after just two days. However, after about day six, it was clear that the plants were not as healthy as they would’ve been if grown in Earth soil, or even as those in the control group that were cultivated in a lunar simulant made from volcanic ash. For example, the plants in the regolith grew more slowly and had stunted roots, and some had stunted leaves and showed reddish pigmentation.
On day 20, just before the plants started to flower, the team harvested the plants, ground them up, and studied the RNA (Ribonucleic acid), a nucleic acid present in all living cells that features structural similarities to DNA.
The results confirmed that the plants had indeed experienced stress, and had responded in a similar way to how Arabidopsis has been observed to grow in other harsh environments, such as in soil with an abundance of salt or heavy metals.
Scientists also established that the quality of the lunar soil varies, as one sample in particular produced poorer growth results than the other two.
The team now plans to use the same regolith to sow more seeds in a bid to find out if the original plants had any effect on the lunar material — in other words, to discover if the plants have in some way conditioned the lunar material so that the next set of plants will find it less harsh.
The study comes as NASA moves ahead with the Artemis program that plans to put humans back on the lunar surface for the first time since the Apollo missions 50 or so years ago, with long-duration missions to Mars also a possibility.
“This research is critical to NASA’s long-term human exploration goals as we’ll need to use resources found on the moon and Mars to develop food sources for future astronauts living and operating in deep space,” said NASA chief Bill Nelson. “This fundamental plant growth research is also a key example of how NASA is working to unlock agricultural innovations that could help us understand how plants might overcome stressful conditions in food-scarce areas here on Earth.”
Astronauts on the International Space Station have also been experimenting with ways to grow edible plants on a habitable satellite, with leafy greens successfully cultivated during years of ongoing space-based research.