There are spores germinated after exposure to space.
Credit: Dr. Chang-hyun Maeng and Maika Kobayashi
Researchers have sent samples of the moss Physcomitrella patens, or spreading earthmoss, to the International Space Station. After nine months on the exterior of the station, the samples have returned in good health. It’s an incredible proof of the plucky plant’s resilience and could suggest a powerful new tool to make space more hospitable to human life.
The study, published in iScience, examines both Earth-bound and orbital experiments, all aimed at assessing the moss’s ability to withstand the pressures of space. The main such issues are the vacuum of space, the radiation of space, and the repetitive cycles of heating and cooling that go on in space.
Not the most hospitable of environments, to say the least.
Thankfully, the researchers found that the earthmoss in question could potentially travel far beyond Earth itself. Samples returned from the ISS showed much the same results as those exposed to terrestrial, simulated space environments: they not only survived, but they continued to germinate.
This is the sort of sample container used to hold the moss on the exterior of the ISS.
Credit: Tomomichi Fujita
Upon return to Earth, all the samples showed high germination rates, with even the samples that were exposed to high levels of UV radiation demonstrating an 86% germination rate.
That’s encouraging, since moss has a greater potential for both oxygen production and low-light survival than algae, and many other crops proposed for cultivation in space. One key downside relative to the potatoes in The Martian, however, is that the moss is not meaningfully edible for humans.
This means that it could be possible for this moss to be frozen, deprived of oxygen, and battered with DNA-shredding radiation, and come out the other side alive and viable. Potentially, that could even be true after multi-year trips to distant star systems. Not only does that augur well for long-term spaceflight, but for (albeit slow) terraforming of alien worlds.
The researchers are quick to point out that this only shows the moss has some of the resilient characteristics needed, but does not prove whether it can, for instance, grow and sustain itself in a zero-gravity or low-gravity environment.
It’s all part of an overall push to think more widely about the future of space. Whether it’s breathing moss-oxygen or eating bug protein, moving into space will likely mean making creative use of the species around us.