Mars is a lifeless wasteland for more than one reason. Not only are temperatures and lack of water difficult for life, the lack of a magnetic field also means that radiation is constantly hitting the surface. If people ever plan to spend any length of time on the Red Planet, they will need to support an additional type of life – plants. However, it seems that even surface greenhouses are not doing enough to protect their plants from the deadly radiation from the Martian surface, at least according to a new paper published by researchers at Wageningen University and Delft University of Technology.
Ideally, agriculture on the Maritan’s surface would consist of greenhouse domes, allowing the limited sunlight that hits the planet to go straight to the plants that house them. However, greenhouse glass is unable to block the deadly gamma rays that constantly irradiate Mars. This gamma radiation, which is around 17 times higher on Mars than it is on Earth, is enough to significantly affect plants grown on the surface in greenhouses.
UT video discussing how to live with in situ resource use on Mars.
The researchers conducted an experiment planting garden cress and rye and measured the harvesting performance of a group irradiated with gamma rays from Mars compared with those grown in a “normal” environment with only earth radiation. The plants in the irradiated group ended up as dwarfs with brown leaves and after 28 days of growth resulted in a significantly lower harvest.
To mimic the gamma-ray environment, Nyncke Tack, an undergraduate researcher who did much of the work on the project, used five separate cobalt-60 radiation sources. These were sprinkled evenly over the test plants to create a “radiation plane” that is similar to the ubiquitous radiation field on Mars.
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Other confounding factors, including the addition of beta and alpha radiation, could also contribute to crop degradation, although solid objects stop these types of radiation more easily. The research team, not surprised by their results, suggests building underground farms where the planet’s regolith blocks most, if not all, of the radiation. This would have the obvious disadvantage of losing access to sunlight, but it would have the added benefit of a much more controllable environment, with LEDs and temperature control filling in the environmental conditions at the surface.
To prove their theory, the team next seizes a Cold War-era bunker in the Netherlands to see if the same irradiation experiments affect the plants grown indoors when the irradiation comes from outside. While not a direct analogue of the Mars regolith, it is a novel approach to understanding how humans might eventually farm the sky.
Wageningen University – growing plants on Mars? Probably not under the naked sun
dezeen – Scientists develop “greenhouse shields” to grow food on Mars
UT – Practical Ideas for Farming on the Moon and Mars
UT – Getting a greenhouse up and running on Mars
Image of mars
Credit – CC0 Public Domain