Making their own moon dirt
NASA is getting closer to sending humans back to the moon through its Artemis program, and understanding the environment and the dirt on the moon is crucial. Humans will be spending time there, living and working on the lunar surface.
However, access to dirt from the moon is extremely limited. Since people can’t grab moon dirt and come back to Earth, lunar regolith is made synthetically in labs.
At the University of Central Florida’s Exolith Lab, managed by the Florida Space Institute, technicians make everything from synthetic moon dust to asteroid regolith. Dan Britt, a Pegasus Professor of planetary sciences at the UCF physics department said this dirt is in high demand.
“Universities buy a lot,” Britt said. “Research Centers buy a lot, and globally, we've had customers in India, South Korea, the European Union, Japan, NASA, all over. Private companies buy a lot, and also schools.
“We're involved in a couple of NASA programs called Plant the Moon, Plant Mars. We provide the regolith that K-12 groups come together and participate in … and try to figure out how to grow plants in this rather forbidding mixture of very difficult stuff.”
Astronauts went to the moon and brought back samples of the regolith. Britt said the lab is able to make it synthetically using those samples.
"The thing is that the moon has kind of a unique geology, and the mineral assemblages that you see on the moon don't occur together on Earth any one place,” Britt said. “You have to get a bit of this from over here and a bit of that from over there and combine them in a very specific way because the Earth is much different from the moon. The primary factors that affect your backyard garden are not going to be cosmic ray bombardment and micrometeorite hypervelocity impacts.”
Britt said a large portion of his synthetic lunar regolith is used for growing plants. Plus, if humans want to stay on the moon for long periods or even live on the moon, that environment must be studied.
“There's a difference between tourism and settlement,” Britt said. “What we've done in the past, at least on the human program, was essentially tourism: show up for a few days and then split. If you're going to be in that environment for long periods of time, you need to really understand the environment and really be able to utilize that to allow you to have a continuous presence. “
Checking in on lunar chickpeas
NASA aims to one day have humans living and working on the moon. But to do that, they’ll need food. So, scientists grew chickpeas in synthetic moon dirt from UCF’s Exolith Lab.
Jess Atkin, a doctoral candidate in the department of soil and crop sciences at Texas A&M, was one of the scientists who grew the legumes in the synthetic dirt. Atkin said because lunar dirt lacks some of the components we have here on Earth, they have to adjust and add certain things.
“On Earth to have a soil, you have to have two things,” Atkin said. “You have to have organic matter, and you have to have microorganisms. When we get to the moon, we don't have any of those things, so that's one of the challenges we had to face.”
Lunar dirt does have some of the things plants need, she said.
It also has things they definitely do not need.
“Besides just the structure, there are a high amount of heavy metals present, specifically in the planned Artemis landing sites,” Atkin said. “We're looking at high levels of aluminum and iron, which can be toxic to plants.”
She explained that chickpeas were chosen specifically because of their tolerance, health benefits and their unique features.
“Chickpeas do well in a lot of environments you put them in,” Atkin said. “They are also really high in protein, up to 22%, so that can help when we're looking at keeping the astronauts’ muscles strong. But my favorite reason is because these plants don't grow alone when they're on Earth. They partner up with microorganisms that can help them access these nutrients and live through these stressors while improving the structure of the regolith.”
Sarah Santos, a post-doctoral scholar at the University of Texas at Austin Institute for Geophysics, worked alongside Adkin on this study. Santos said their project takes humanity one step closer to the goal of growing plants on the moon in real lunar regolith.
“I'm not going to claim that our method is going to solve all the issues, because we really control for a lot of variables,” Santos said. “So, the chickpeas have ideal watering cycles, ideal light. They're not being grown in reduced gravity. They don't have the risks of radiation.”
They’re focusing on just one of the hazards on the moon, she said. There's a lot of research to be done, but if we can provide the ideal conditions, and the only hazard that the chickpeas or other plants have to deal with is the regolith, I'd say that our method gets us pretty close.”
