For space explorers, it is evident that we will want to grow plants in lunar soil and other planets one day. It was unknown in a lunar greenhouse; how or if the plants would grow?
Could we farm food on the Moon?
This question has now been answered.
Scientists had to wait 11 years for a tiny amount of old moon dirt
Over 11 years, scientists Anna-Lisa Paul and Rob Ferl applied three times for an opportunity to work with the lunar regolith (Moon dirt). Their persistence paid off, and NASA has loaned them a few grams of Moon dirt.
Using just a few teaspoons (12 grams) of lunar soil collected during the Apollo 11, 12, and 17 missions, University of Florida scientists led by professor Rob Ferl have now proved that they can grow plants in lunar soil. Their findings are published in a new study report in Communications Biology on May 12, 2022.
Paul and Ferl are world-renowned experts in plant research in space. They’ve sent experiments on space shuttles to the International Space Station and suborbital missions through the UF Space Plants Lab.
This experiment has helped them establish that the soil samples from the Moon did not include diseases or other unknown components that could affect terrestrial life.
This study is a first step toward growing food and oxygen-producing plants on the Moon or during future space missions. This research comes when the Artemis Program plans to return humans to the Moon.
The scientists anticipate we may be able to use the Moon as a hub or launchpad for future, longer space expeditions.
Creating a deceptively easy experiment, Paul and Ferl planted seeds in lunar soil, added water, nutrients, and light, and recorded the outcomes.
Due to the small amount of dirt and its enormous historical and scientific value, they had to devise a carefully coordinated small-scale experiment.
They filled thimble-sized pots with around a gram of lunar soil; the scientists hydrated the soil with a fertilizer solution. After filling each “pot” with around a gram of lunar soil, they added a few seeds from the Arabidopsis plant.
The Arabidopsis plant’s genetic code is thoroughly mapped. Growing Arabidopsis in lunar soil gave researchers a more detailed understanding of how the soil affected the plants.
Arabidopsis was also planted in JSC-1A, a terrestrial substance that replicates proper lunar soil and simulated Martian soils and terrestrial soils from harsh conditions, as a point of comparison. The experiment also compared plants grown in non-lunar soils (e.g., Earth’s soil).
The researchers were unsure whether the seeds put in the lunar soils would sprout before the experiment. However, almost all of them did. This indicates that lunar soils do not interfere with plant germination hormones and signals.
Plants planted in lunar soils compared to plants planted in Earth soil were smaller, grew more slowly, and had a more comprehensive range of sizes than their terrestrial counterparts. This indicates physical evidence that the plants were attempting to adapt to the Moon’s soil chemical and structural make-up.
The scientists could infer that the plants view the lunar soil environment as stressful. Plants had to adapt to salt, metals, or oxidative stress.
The researchers would like to use the gene expression data to help them figure out how to reduce stress responses to the point where plants, particularly crops, can grow in lunar soil with minimal health consequences.
How plants respond to lunar soil depends on where the soil is collected
Ferl and Paul, who worked on the project with Stephen Elardo, an assistant professor of geology at UF, believe that how plants respond to lunar soil depends on where the soil is collected.
Cosmic wind, over time, changes the composition of the soil. Plants struggled to grow in lunar soil most exposed to cosmic wind, known as mature soils. Plants cultivated on lunar soils with less exposure to cosmic winds performed better.
The Moon can potentially become more plant-friendly
Elardo believes that growing plants in lunar soils could alter the dirt themselves.
The Moon is an arid environment; Elardo wonders how the minerals in the lunar soil react to adding water and nutrients from a plant? Will adding water to the mineralogy make it more plant-friendly?
Hopefully, this experiment paves the way for scientists to conduct experiments with more significant amounts of Moon soil.
Maybe one day, the Moon will supply the future Moon citizens with fresh food?
Feature image credit: NASA and UF/IFAS photo by Tyler Jones