Scientists germinate first-ever seedlings in Apollo Moon Dirt

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Twelve grams of the moon arrived at Robert Ferl’s lab in an undecorated UPS box.

Ferl, a horticulturist at the University of Florida, had waited more than a decade for this moment. The small dirt box, postmarked by NASA, contained some of the last unopened samples of moon dust, or regolith, collected by astronauts on Apollo 11, 12 and 17 assignments. Despite months of practice, Ferl recalls, he lifted the sample with shaky hands. “It’s weird, scary. I mean, what if you drop that?” he says. Ferl and his team were set to become the first researchers to grow plants in soil. real lunar.

The experiment has been greenlit as part of a recent lunar research boom fueled by NASA’s Artemis program, which aims to return humans to the moon later this decade. This time around, NASA wants to explore the Moon in a more sustainable way by creating surface outposts for longer stays, as well as a lunar-orbiting space station called Gateway – two essential dress rehearsals, according to the space agency, for possible astronautical journeys to Mars. . Scientists believe these longer missions will require a sustainable source of food. “All human exploration has been driven by the ability to feed crews,” says Gil Cauthorn, a researcher based in Osaka, Japan, at the Astrobotany International Research Initiative.

Ferl’s research, which was published in Communications Biology in May, offers an important first step in this journey, finally proving that plants can grow in lunar soil. However, the seedlings didn’t really thrive in the regolith alone, indicating that future lunar farmers will need to fertilize their soil before planting crops.

In order to test the lunar soil, Ferl and his team divided the samples into 12 pots of 900 milligrams each and planted in each seed of Arabidopsis thaliana (a hardy relative of mustard and cabbage that is a standard “model organism” in biology). To their delight, all the seeds germinated successfully. Yet the seedlings struggled with the next stage of growth: establishing a healthy root system. “That turned out to be quite problematic,” says Ferl. Apollo sprouts were slow to develop and showed signs of extreme stress associated with too much salt, metal and soil oxidation. It has a lot to do with the supernatural conditions in which the lunar regolith formed – it was hammered by solar winds, cosmic rays and meteorite impacts over billions of years. But just as crucial are the ingredients it lacks, namely water and microbes.

Microbes are among the most important components of any soil. “They play a huge role,” says Gretchen North, a plant physiology ecologist at Occidental College, who was not involved in the study. Symbiotic bacteria help plants regulate growth hormones, fight pathogens, minimize environmental stress, and absorb essential nutrients such as nitrogen. However, lunar regolith does not have a natural microbiome. Without this complex biological web, plants grown in the lunar earth struggled to manage nutrient uptake and stress.

Lack of water can also change the consistency of the soil for the worse. Regolith, which is a strictly non-biological material, can become extremely dense like cement when water is added. “It’s hard to keep this stuff from becoming a rock,” says Cauthorn.

But that doesn’t necessarily mean that lunar regolith can’t be turned into viable soil by adding extra nutrients or composting crops to encourage the growth of microbes. Even taking the soil as is, it is possible that the plants could survive for a generation or two as they become established. “Cultivated plants are really capable of tightening their belts and growing small,” says North. Yet without proper soil development, “after a while they probably wouldn’t do the important things that we need crops for.”

Despite these nutritional and microbial obstacles to lunar agriculture, North, who has studied plant growth under simulated Martian conditions, believes the moon offers more fertile soil than the rusty soil of the Red Planet. This is because Martian regolith is full of perchlorate, an oxidizing compound that stunts plant growth and can be harmful to humans.

Sooner or later, the ability to grow crops beyond Earth will become vital to living and working in space. Whether in orbital habitats or on long interplanetary journeys, plants could not only be sustainable food sources, but also useful components of a life support system by producing oxygen and cleaning the air of excess carbon dioxide. “Growing plants is part of learning how to survive and thrive in the space environment you’re supposed to work in,” says Jake Bleacher, chief exploration scientist at the Exploration Missions Directorate. and NASA Human Operations, which also was not involved in Cauthorn’s study. Additionally, methods of growing crops from otherworldly regoliths could also be useful for managing agriculture in extremely nutrient and water-depleted soils right here on Earth.

“Most of us won’t go to space,” says Cauthorn. “But if we can devise a way to produce these kinds of crops in such an unforgiving environment, like the lunar surface, we can apply it to meet our food challenges in regions that simply can’t produce food anymore.”

In the future, Ferl would like to continue studying how life might take hold in otherwise barren extraterrestrial soils. But for now, he and his fellow researchers are grateful for the opportunity to experience one of the only pieces of lunar soil on Earth. “For us, it has been and continues to be a real privilege,” he says.

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