In March of last year, a group of Dutch scientists announced that they had grown 10 different plant species—including tomatoes, peas, rye, garden rocket, radish and garden cress—in dirt engineered to mimic the harsh, arid soil of Mars.
A new study suggests that potatoes may be able to survive on the Red Planet, too. As Katherine Ellen Foley reports for Quartz, researchers at the International Potato Center (known as CIP, its Spanish acronym) were able to sprout a crop of spuds in Mars-like soils.
Scientists working on the aptly named "Potatoes on Mars" project wanted “to know what the minimum conditions are that a potato needs to survive,” researcher Julio Valdivia-Silva says in a statement. But the scientists faced a steep challenge. Conditions on Mars are not hospitable to biological life. The planet’s soils are salty, thin, and lacking in chemicals like nitrogen, which helps plants grow. Its atmosphere contains little oxygen—also important to plant growth—and its average temperature hovers at a frigid -80 degrees Fahrenheit.
To mimic the harsh surface of Mars, researchers relied on soils from the Pampas de La Joya desert in Peru, which, like the soils on the Red Planet, contains few life-sustaining compounds. Researchers took a number of steps to boost the potatoes’ chances of growing in such a challenging medium. They used tubers that had been bred to thrive in salty soils, and irrigated them with nutrient-rich water. As Rae Paoletta points out in Gizmodo, the soil was also enhanced with fertilizer—not unlike Matt Damon’s poopy potato crops in The Martian.
They placed the soil inside a CubeSat—a small, sealed device—and sowed the dirt with potato seeds, Rob LeFebvre reports for Engadget. Within the device, the potatoes experienced elevated carbon dioxide levels and low pressures to mimic Mars conditions, according to the release. The exact pressure and gas composition used within the device, however, remains unclear. And as Paoletta notes, the researchers could not have simulated the extreme temperature swings of the Red Planet's surface without killing off their spuds.
It's unlikely potatoes will ever be grown freely on the surface of Mars. As ecologist and exobiologist Wieger Wamelink, who studies produce growth in Mars-like soils, explained in a 2016 press release: "[W]e expect that first crop growth on Mars and moon will take place in underground rooms to protect the plants from the hostile environment including cosmic radiation."
Sensors monitored the patch of land 24 hours a day. And one year after the project began, researchers saw spuds sprouting in the soil. Potato breeder Walter Amoros calls the results a “pleasant surprise,” according to the CIP statement.
CIP’s experiment could have significant implications for the future of space exploration. NASA is pushing forward with plans to send humans to Mars, and astronauts are going to need to eat while they’re there. But it’s important to note that the results of the experiment have not yet been published in a peer-reviewed journal.
Growing the plants is just the first hurdle that scientists need to overcome when it comes to feeing astronauts on Mars. More researcher is necessary before future space travelers can freely chow down on potatoes grown in Mars-like soils. As Wamelink explained last year: "The [Mars-like] soils contain heavy metals like lead, arsenic and mercury and also a lot of iron. If the components become available for the plants, they may be taken up and find their way into the fruits, making them poisonous." And as Foley reports for Quartz, there's still many logistics that must be addressed. “[F]iguring out how to bring the seeds, water, and plant nutrients to our neighboring planet is something else entirely,” she writes.
The results of the experiment, however, may be even more significant to humans here on Earth than distant travelers. When CIP isn’t dabbling in extraterrestrial farming, the organization uses roots and tubers to develop sustainable solutions to poverty, hunger, and climate change across the globe. Climate change creates poor soil conditions, the CIP explains in a second statement, which can exacerbate poverty and malnutrition in already vulnerable areas. If potatoes can thrive in Mars-like conditions, researchers theorize, they can likely survive in soils that have been damaged by global warming. Or as Joel Ranck, CIP’s Head of Communications, puts it: “[I]f we can grow potatoes in extreme conditions like those on Mars, we can save lives on Earth.”
Editor's note March 20, 2018: This story has been updated to emphasize the challenges scientists still face in growing potatoes on Mars. It also clarifies that any future potatoes grown on the Red Planet will likely be housed in subsurface enclosures.