Growing a Victory Garden on Mars
Like many other people during the early days of the pandemic, I planted a garden. Sinking my hands into the topsoil to plant carrot and tomato seeds brought with it a sense of control in an otherwise chaotic time. I knew that if I fertilized and watered my new plants, they would provide me with fresh, healthy vegetables by early summer.
Except they didn’t.
Despite my care and attention, the tomatoes never ripened, and the carrots were never more than stunted orange nubs. I ate them anyway — the carrots were tasty, but the half-ripened tomatoes were mealy and flavorless — but I was glad I didn’t have to rely on my gardening skills to survive the pandemic. As long as I put a mask on, I could still get my food from the grocery store.
If I were one of the future explorers on Mars, though, I wouldn’t have that luxury. The feasibility of manned exploration of the red planet depends in part on whether or not we can feed ourselves when we get there. A plant-based diet would be the least resource-intensive, but is it even possible on Mars?
The answer to that question begins with regolith, the loose rock and debris that covers most the Martian surface. We know a lot more about the regolith on the red planet since NASA landed the Spirit and Opportunity rovers there in 2004. Subsequent missions have bolstered our understanding of the composition of the planet’s surface and its potential to support life. The ability to grow food directly in the Martian soil is essential since it isn’t practical to haul topsoil all the way from Earth. Martian explorers will have to be self-sufficient.
To make sure explorers don’t end up with a disastrous garden (like mine), scientists are using data from the rover missions to recreate Martian soil here on Earth. Laura Fackrell, a doctoral student at the University of Georgia, recently published a study on the potentials and limitations of growing plants in Mars-like conditions. Martian soil is known to contain the essential nutrients for plant growth — primarily nitrogen, potassium and phosphorus. However, that’s only part of the challenge. Nutrients need to be present in the right amounts and in the right chemical forms for plants to make use of them.
The first step in growing the perfect Martian garden might be selecting the right location. Soil composition varies across the planet’s surface, and in some places it could be toxic to plants. The ideal location would contain the basic nutrients for plant life without harmful toxins like salts and perchlorate, both common on Mars. This raw material could then be inoculated with healthy bacteria or fungi, along with other soil amendments brought from Earth.
While Fackrell’s research focuses on Mars, it’s also applicable to any future colonization of the moon. “We would also need to use materials on the surface to help maximize use of weight and space, and the moon can act as a preparatory ground…for Mars,” says Fackrell. Colonizing the moon will be challenging, but the risks are lower due to its closer proximity to Earth.
After reading about Fackrell’s research, there was still one thing I wanted to know: Did Matt Damon get it right in The Martian? Could someone actually grow poop potatoes on Mars? Fackrell was kind enough to indulge me with an answer. “He got it at least partially right.” If he happened to pick exactly the right Martian soil to start with, organic material (i.e. human waste) could provide missing nutrients. It might work, but “more experiments are needed to really get into the ‘dirty details.’”
In light of this new research, future explorers will thankfully have more options for dinner.
“Development of Martian regolith and bedrock simulants: Potential and limitations of Martian regolith as an in-situ resource”