Researchers have successfully grown a crop of tomatoes, peas and radishes harvested in Martian soil — and with those comes an answer to one of the big questions we have about how to farm in space. Since 2014, researchers from Wageningen University in the Netherlands, led by ecologist Wieger Wamelink, have been experimenting with growing vegetables in NASA's simulated soil from Mars and the Moon. They had some early success with germinating plants in both the lunar and Martian soils. But now they have managed something bigger.
Tomatoes, peas, rye, garden rocket, radishes and garden cress were all successfully harvested from simulated Moon and Martian soil — and there was also one surprise in that harvest. The vegetables grown in the Martian soil were almost exactly the same size as their Earth counterparts, and there were barely any differences in total biomass by the harvest date, according to Wamelink.
Comparison of peas grown in Lunar (1st), Martian (2nd), and Earth (3rd) soil / Wieger Wamelink
Of course, even with a successful harvest in Martian soil out of the way, there would still be significant obstacles to actually setting up a farm on the surface of Mars. Not only are there all the technical, budgetary and timing issues of getting a mission up there, but you also have the problems of setting up life support and a farm. Martian farms would need clean sources of water, reliable light (perhaps electrically-driven) and big swatches of enclosed space, none of which would come easily.
This experiment tells us that solving all those tricky problems is worth that effort. Because, when we do, there is soil up there that could support vegetables of similar sizes to the ones we have on Earth. There's also another big question that these new Martian vegetables could finally answer for us: How do they taste? Alas, the mystery of whether the dry, Martian soil picks up any surprising flavours remains for a little while longer.
Tomato plants grown in Martian soil / Wieger Wamelink
"We had crops and harvested them, tomatoes, rye grains, radish, rocket, cress, but did not taste them yet," Wamelink told Gizmodo. "First we have to make sure that it is safe to eat them because of the heavy metals that are present in the soils and may end up in the plants. This year's experiment will therefore all about food safety and nutritional value."
However, once they have finished testing heavy metal content — assuming all looks good — Wamelink tells us that the next round of vegetables will get a taste test. For the moment, though, it's still more a question of survival than taste.
Top image: Artist's concept of astronauts on Mars / NASA/ JPL-Caltech