Scientists have grown seeds in moon soil for the first time, using samples collected during NASA missions in 1969 and 1972. This achievement heralds the promise of using earthly plants to support human outposts on other worlds.
Researchers said they planted seeds of Arabidopsis thaliana, a small flowering weed, in 12 small thimble-sized containers each containing a gram of lunar regolith on May 12 and watched them sprout and grow. Because lunar regolith differs greatly from Earth soil in terms of sharp particles and lack of organic material, it was unknown whether seeds would germinate.
“When we first saw that abundance of green sprouts cast over all of the samples, it took our breath away,” said horticultural sciences professor Anna-Lisa Paul, director of the University of Florida Interdisciplinary Center for Biotechnology Research and co-leader of the study published in the journal Communications Biology. “In the lunar regolith, plants can grow. That one simple statement has enormous implications for future exploration of the moon and, most likely, Mars “Ms. Paul explained.
Seed germinated on Moon
Every seed germinated, and there were no visible differences between seeds sown in the regolith – mostly crushed basalt rocks – and seeds sown in volcanic ash from Earth with similar mineral composition and particle size at the early stages of growth.
Regolith seeds performed worse than the comparison plants, which is perhaps unsurprising. They grew more slowly and were generally smaller, had more stunted roots, and were more likely to show stress-related characteristics like smaller leaves and a deep reddish-black coloration that was not typical of healthy growth. They also showed stress-related gene activity, similar to plant responses to salt, metal, and oxidation.
Ms. Paul explained, “Even though plants could grow in the regolith, they had to work hard metabolically to do so.”
Outstanding achievement
The fact that they grew at all was remarkable to the researchers. Rob Ferl, an assistant vice president for research at the University of Florida, said he felt “joy at watching life do something that had never been done before.”
“Seeing plants grow is an accomplishment because it implies that we can go to the moon and grow food, clean the air, and recycle water using plants in the same way we do on Earth. It’s also a revelation because it asserts that terrestrial life isn’t restricted to Earth “Mr. Ferl continued.
Because of its rapid life cycle and deep understanding of its genetics, Arabidopsis, also known as thale cress, is widely used in scientific research, including previous experiments in space.
NASA made 12 grams of regolith (a few teaspoons) available from the Apollo 11, Apollo 12, and Apollo 17 missions. Three or four seeds were planted in a dozen containers that had been moistened with a nutrient solution, then placed in a laboratory at 73 degrees Fahrenheit (23 degrees Celsius) under pink LED lights.
Within three days, the seeds sprouted. The researchers removed all but one plant from each container after about a week of growth. The one was allowed to grow for 20 days before its leaves were harvested to test gene activity.
The researchers also discovered that regolith on the lunar surface that had been exposed to cosmic rays and solar wind for longer periods of time was less conducive to growth.
Plants on Earth could aid in the establishment of outposts on the moon and Mars
Plants on Earth could aid in the establishment of outposts on the moon and Mars, as depicted in the 2015 film “The Martian,” in which an astronaut grows potatoes on Mars. People will return to the moon’s surface in the coming years, according to NASA’s Artemis program.
“Plants are deeply embedded in the science of space exploration because of their life-support role,” Mr. Ferl explained.