Rocket salad, anyone? Veg study looks at greens on red planet
Scientists have taken a leaf out of The Martian script by showing how easy it would be to grow your own veg on the Red Planet.
In the hit Ridley Scott movie, stranded astronaut Mark Watney, played by Matt Damon, survives on Mars by using his botanical skills to cultivate potatoes.
Now his success has been emulated by researchers in the Netherlands. In an experiment that would make Monty Don proud, they harvested tomatoes, peas, rye, rocket, radish and garden cress raised on simulated Martian soil.
Yields were unexpectedly high and matched those of vegetables grown in ordinary potting compost.
Lead scientist Dr Wieger Wamelink, from Wageningen University, said: "That was a real surprise to us. It shows that the Mars soil simulant has great potential when properly prepared and watered."
The same crops flourished less well in simulated moon soil, producing half as much biomass - but they still grew.
It was the second attempt by the team to test out the kind of gardening that might be carried out by future settlers on the moon and Mars.
Improvements were made by using trays instead of small pots and adding a mulch of organic material in the form of fresh-cut grass.
In the first experiment, most of the "moon" plants died.
Both soils were supplied by the American space agency Nasa and designed to mimic their real counterparts as closely as possible. The "Martian" soil was obtained from a Hawaiian volcano and the "lunar" soil from the Arizona desert.
Dr Wamelink said: "Martian soil is really very good, something between clay and sand, and a bit loamy. It's a fine, nutrient-rich soil. The main thing that's lacking is nitrogen.
"After the first experiment I was convinced that we would be able to grow crops we could harvest, but I never guessed it would go so well."
The fact that the surface of Mars is heavily irradiated would make no difference to cultivating crops in protected habitats, he added. Gardening outside, under a constant bombardment of energetic particles, would be impossible.
A total of 10 different crop species (tomato, rye, radish, pea, leek, spinach, rocket, cress, quinoa, and chives) were successfully grown, and six harvested. The only major failure was spinach, which proved a poor candidate for interplanetary horticulture.
Plants were cultivated in a glass house under regulated temperature, humidity and light conditions and surrounded by an Earth atmosphere.
"This is because we 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," said Dr Wamelink.
Unlike Watney, the scientists were not willing to risk eating the Mars and moon veg they had grown.
Dr Wamelink explained: "The 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. Further research on this is necessary."
With this in mind, a crowdfunding campaign has started to finance a third experiment that will focus on food safety.
The study should begin next month with the growth of a new batch of crops including potatoes and beans.
If they prove safe enough to eat, members of the public who have donated money to the research will be invited to dinner and served a "Martian meal" containing the harvested vegetables.