As populations grow, extending humanity to other planets is an increasingly viable solution to overpopulation. But for us to live on other planets, we would need a stable environment and community, which inevitably involves plants. Plants are the starters of the food chain: without their ways of converting light energy from the Sun into chemical energy, we would not be able to survive.
But growing plants in, for example, the moon, presents many problems. For one, there is a very weak gravity. In previous experiments, plants grown in microgravity have not done too well: they grow in weird shapes, develop unusual genetic mutations and produce seeds which don’t germinate.
However, a new method seems to solve these problems. It uses a capsule where the plant lives, and the soil that it needs to survive is kept ‘down’ using a net. The container, designed by scientists at University of Wisconsin-Madison, controls all abiotic factors: light, temperature, moisture, carbon dioxide and oxygen concentration… and has been sent into space to rest in the ISS (International Space Station) for months. However, it has been monitored from millions of kilometres away in the university itself.
This new model has proven much more successful than other attempts, and the plant sent, a Arabidopsis thaliana, has grown perfectly well, albeit with some oddly shaped branches. In fact, a control experiment set up on Earth showed that the two plants were not actually that different from each other. But that doesn’t actually matter too much; what’s important is that the plant in space has produced viable seeds which can germinate and grow into new plants. This is precisely what future populations living in other planets want, as this means they can have a sustainable, self-renewing farm.
Another important factor is soil quality. Both the moon and Mars are made out of basaltic and volcanic material, so experiments here in Earth imitating conditions there use volcanic soil.
Most have generated fairly positive results: without adding any new nutrients, volcanic soil by itself was able to grow a variety of plants for 50 days. The only problem was water: most planets in our Solar System don’t actually contain water, so the water necessary to grow the plants would have to be provided by the astronautic farmers.
As always, more research is needed, but the prospect of growing plants in space to feed large populations does not seem too far from the nearby future. And the research put into this objective could have repercussions and applications in the present, for example, in plant engineering to maximise crop yields.