An ongoing study has shown it might be possible to grow potatoes on Mars. Scientists in Peru are replicating conditions there in order to test potato varieties to see if they could survive extreme conditions like sub-zero temperatures, high carbon monoxide concentrations and low air pressure equivalent to being at 6km altitude.
In addition, the soil being used is highly saline. It was taken from the Pampas de la Joya on Peru's southern coast which receives less than 1mm of rain each year. 700kgs of this unwelcoming earth were transported to Lima for the experiment, where it was placed in sealed boxes rigged to imitate conditions on Mars.
Scientists decided to investigate the extremes at which potatoes could be grown, not because humans are planning a big move into space, but more because with climate change, parts of our own planet might begin to resemble the final frontier. "It's not only about bringing potatoes to Mars, but also finding a potato that can resist non-cultivable areas on Earth," according to astrobiologist Julio Valdivia from Peru's University of Engineering. Valdivia is working with NASA on the project.
Out of 65 varieties of potato that were planted, just four sprouted and the best performer was, fittingly, a variety called Unique. "It's a 'super potato' that resists very high carbon dioxide conditions and temperatures that get to freezing," Valdivia was quoted as saying.
The experiment was partially inspired by a 2016 film, The Martian, in which an astronaut gets stranded on the red planet where he manages to grow potatoes to sustain himself. Peru was considered a fitting country in which to conduct the experiment as the potato came from Peru, and its mountainous terrain offers some natural extremes comparable to outer space.
This was only the first phase of the experiment and did not entirely match the actual extremes of Mars. It is believed to be impossible to grow anything outdoors on Mars because of its cold temperatures, low atmospheric pressure and lack of oxygen, but perhaps within greenhouses some plants could survive there. A second phase will ramp up the extremes to match actual conditions plants would experience on Mars.
Regardless of whether or not humans colonise outer space, knowing the ability of plants to survive extremes could be useful to those of us here on Earth if climate change passes a tipping point, that leads to extreme weather becoming the norm. Parts of our planet that are currently temperate, like Ireland, could become hostile if, for example, the Gulf Stream was disrupted. In such a scenario access to hardy food varieties would be very important.