GAINESVILLE, Fla. — Food has been grown in soil collected from the Moon for the first time, paving the way for human colonization of the solar system. Pioneers would be able to cultivate crops on other worlds, mirroring the plot of the movie “The Martian.”
In a case of life imitating art, scientists have cultivated cress in dirt, or regolith, that had been kept since the Apollo missions — a half-century ago! It is a first step towards producing food and oxygen on the Moon or during future space missions.
Over the next decade, NASA’s Artemis program will lay the foundation for a sustained colony on the lunar surface. The project will use Earth’s lone satellite to validate deep space systems and operations before embarking on a manned voyage to Mars.
“Artemis will require a better understanding of how to grow plants in space,” says co-author Professor Rob Ferl in a university release.
Crops on the Moon would make space travel cheaper
A moon base would make spacecrafts much lighter and cheaper. Earth’s atmosphere and gravitational pull mean tons of fuel per second are needed to lift off. Moreover, the moon is a treasure trove of valuable resources. Gold, platinum, and other rare metals for next-generation electronics are awaiting extraction.
“For future, longer space missions, we may use the moon as a hub or launching pad. It makes sense that we would want to use the soil that’s already there to grow plants,” Prof. Ferl says. “So, what happens when you grow plants in lunar soil, something that is totally outside of a plant’s evolutionary experience? What would plants do in a lunar greenhouse? Could we have lunar farmers?”
The University of Florida team planted seeds in lunar soil picked up by the Apollo 11, 12, and 17 crews between 1969 and 1972. They added water, nutrients, and light before watching the edible spring salad green flourish.
A tiny “lunar garden” was created from just a few teaspoons of the prized dirt specially loaned from NASA. Researchers were granted 12 grams after 11 years of negotiations with the space agency. Thimble-sized wells in plastic plates normally used to culture cells were filled with a gram of lunar soil.
They were moistened with a cocktail of nutrients. Then, a few seeds of cress were added to each pot. The horticulturalists weren’t sure if they would sprout, but nearly all of them did.
“We were amazed. We did not predict that,” says co-author Prof. Anna-Lisa Paul. “That told us that the lunar soils didn’t interrupt the hormones and signals involved in plant germination.”
Just like in the movies!
It opens the door to “resource independence” from Earth. NASA and Elon Musk’s SpaceX are committed to sending people to Mars in the near future. However, the logistical challenges are huge. Transporting food all the way from Earth would be impractical. Producing it locally is imperative.
Damon’s character in the sci-fi blockbuster fertilizes Martian soil with feces, slicing potatoes and planting the cuttings. He grows enough food to last hundreds of days. Even in the early days of lunar exploration, plants played an important role, Prof. Paul says.
“Plants helped establish that the soil samples brought back from the moon did not harbor pathogens or other unknown components that would harm terrestrial life, but those plants were only dusted with the lunar regolith and were never actually grown in it,” Paul adds.
Paul and Ferl are internationally recognized experts in the field of plants in space. They have sent experiments on space shuttles, to the International Space Station, and on suborbital flights.
Seeds can learn to grow in Moon dirt
Thale cress, or Arabidopsis, is native to Europe, Asia, and Africa. It is widely used in research because its genetic code has been fully mapped. Cultivation in the lunar soil sheds fresh light on how plants would be affected, down to the level of gene expression.
Seeds were also planted in basaltic and volcanic ash from earth, as well as simulated Martian soils, which acted as controls. Over time, differences were observed. Some lunar plants were smaller, grew more slowly, or were more varied in size than their counterparts. These were signs they were working to cope with the chemical and structural makeup of the Moon’s soil — which was confirmed by gene expression analysis.
“At the genetic level, the plants were pulling out the tools typically used to cope with stressors, such as salt and metals or oxidative stress, so we can infer that the plants perceive the lunar soil environment as stressful,” Paul reports.
“Ultimately, we would like to use the gene expression data to help address how we can ameliorate the stress responses to the level where plants — particularly crops — are able to grow in lunar soil with very little impact to their health.”
The study also found plants with the most signs of stress were those grown in what geologists call mature lunar soil. Exposure to more cosmic wind alters their makeup. Those grown in comparatively younger soils fared better. Growing may also change the soils themselves.
“The moon is a very, very dry place. How will minerals in the lunar soil respond to having a plant grown in them, with the added water and nutrients? Will adding water make the mineralogy more hospitable to plants?” says co-author Dr. Stephen Elardo.
Food on the Moon? The answer is yes
Follow-up studies will build on these questions and more. For now, the researchers are celebrating “growing plants on the Moon.”
“We wanted to do this experiment because, for years, we were asking this question: Would plants grow in lunar soil,” Ferl concludes. “The answer, it turns out, is yes.”
The Moon is the gateway to the solar system. Over the coming decades, humans hope to use the satellite’s extensive resources, including water and metal deposits. Exploration will enable groundbreaking discoveries about the universe through radio astronomy from the incredible vantage point on its far side.
South West News Service writer Mark Waghorn contributed to this report