In the early days of the space age, Apollo astronauts had a visionary plan to bring back samples of the lunar surface material, known as regolith, so they could study it with state-of-the-art equipment and use it in future research. Now, 50 years later, as we are beginning the Artemis era and returning astronauts to the moon, three of those lunar samples have successfully grown plants. Researchers grew the hardy and well-studied Arabidopsis thaliana in the nutrient-poor lunar regolith.
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. 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.
A breakthrough discovery of scientists at the University of Florida.
Scientists at the University of Florida make a breakthrough discovery that can both enable space exploration and benefit humanity.
Robert Ferl, a professor in the University of Florida’s Horticultural Sciences department, was a communicating author on a study published in the peer-reviewed journal Communications Biology on May 12, 2022. Ferl said:
Here we are, 50 years later, completing experiments that were started back in the Apollo labs. We first asked the question of whether plants can grow in regolith. And second, how might that one day help humans have an extended stay on the moon.
To the first question, the answer is a loud yes. In lunar regolith, plants can grow. They weren’t as robust as plants growing on Earth soil or even those in a lunar simulant made of volcanic ash in the control group, but they did grow. The team wants to address the second question by researching how the plants responded in the lunar samples, paving the way for future astronauts to grow more nutrient-rich plants on the Moon and live in outer space.
To boldly go, we must boldly grow
Jacob Bleacher is the Chief Exploration Scientist supporting NASA’s Artemis program at NASA Headquarters in Washington. Bleacher points out NASA is sending robotic missions to the moon’s South Pole to search for water that future astronauts can use. Bleacher said:
To explore further and to learn about the solar system we live in, we need to take advantage of what’s on the moon, so we don’t have to take all of it with us. What’s more, growing plants is the kind of thing we’ll study when we go. So, these studies on the ground lay the path to expand that research by the next humans on the moon.
Arabidopsis thaliana is a relative of mustard greens and other cruciferous vegetables including broccoli, cauliflower, and Brussels sprouts. It is native to Eurasia and Africa. It’s also important to scientists: because of its small size and ease of development, it’s one of the most researched plants on the planet, and it’s used as a model organism in plant biology research. As a result, scientists already know how it responds in various situations, how its genes look like, and how it grows in space.
Working with teaspoon-sized samples
The team used samples from the Apollo 11, 12, and 17 missions to cultivate the Arabidopsis, with only a gram of regolith allotted for each plant. The samples were then filled with water and seeds. They then put the trays into terrarium boxes in a clean room. Every day, a nutrient solution was added.
A professor in Horticultural Sciences at the University of Florida and first author on the paper, Anna-Lisa Paul, said:
After two days, they started to sprout! Everything sprouted. I can’t tell you how astonished we were! Every plant – whether in a lunar sample or in a control – looked the same up until about day six.
After day six, the plants were not as robust as the control group plants growing in volcanic ash, and the plants were growing differently depending on which sort of sample they were in. The plants grew more slowly and had stunted roots, as well as stunted leaves and reddish coloring in certain cases.
After 20 days just before the plants started to blossom, the team picked the plants, ground them up, and examined the RNA. In a biological system, genes are decoded in multiple steps . First, t he genes, or DNA, are transcribed into RNA. The RNA is then converted to a protein sequence. Many of the biological functions in a living creature are carried out by these proteins. Sequencing the RNA revealed the gene expression patterns, indicating that the plants were stressed and had behaved similarly to how Arabidopsis has reacted to growing in other severe settings, such as when the soil contains too much salt or heavy metals.
Additionally, the plants behaved differently depending on which sample was utilized, which was obtained from various locations on the Moon. The Apollo 11 samples produced less vigorous plants than the other two groups. Despite this, the plants grew.
Sowing the seeds for future research
This study opens the door to a slew of new concerns, including how to cultivate plants in lunar homes in the future. Can figure out which genes, plants need to respond to growing in regolith help us figure out how to make lunar soil less stressful? Are there minerals on the Moon that are better for growing plants than others? Could researching lunar regolith aid our understanding of Mars regolith, as well as the possibility of cultivating plants in that material? All of these are issues that the team plans to investigate further in the future to help future astronauts traveling to the Moon.
A program scientist with NASA’s Biological and Physical Sciences Division, Sharmila Bhattacharya, said:
Not only is it pleasing for us to have plants around us, especially as we venture to new destinations in space, but they could provide supplemental nutrition to our diets and enable future human exploration. Plants are what enable us to be explorers.
On the end, scientists were able to successfully cultivate plants in lunar soil. This is critical for future space missions that may involve humans residing on the moon or another planet.