By: Tanvi Ambekar

Opinion Editor

Although Earth’s life forms are incredibly diverse, most cannot survive more than a few seconds in the vacuum of outer space. However, a recent study found that spores of some moss species endured nine months of cosmic radiation and were still able to germinate after returning to Earth.

Japanese scientist Tomomichi Fujita at Hokkaido University led this study that focused on Physcomitrium patens, more commonly known as spreading earthmoss. This moss thrives in many extreme environments, including, according to ScienceDaily News, “the scorching deserts of Death Valley, the Antarctic tundra, and the cooling surfaces of active volcanoes,” leading the team to wonder whether its cells might also withstand the conditions of outer space. 

The researchers tested cells from three life stages of the moss: protonemata, brood cells, and sporophytes. Extreme temperatures and ultraviolet light quickly killed the protonemata. The brood cells fared somewhat better, but sporophytes proved most resilient with nearly 1,000 times greater radiation resistance, and surviving both deep-freeze and intense heat treatments. 

With cautious optimism, the team launched hundreds of dried sporophyte capsules to the International Space Station (ISS) in March of 2022 to be mounted on a small exposure panel outside Japan’s Kibō laboratory module. After 283 days in the vacuum of space, subjected to radiation and solar UV, scientists retrieved and tested for viability; more than 80% of the spores had survived, and most successfully germinated into healthy moss. Fujita and his team suggested that the spores’ resilience stems from the nature of their protective coverings, which absorb UV radiation and shield the DNA inside.

For future astronauts and space biologists, this discovery points to moss not as a food source but as a foundation for interplanetary infrastructure. Moss is compact, needs little soil, and can photosynthesize under minimal light. Dense mats could one day support future Mars or moon bases by trapping moisture, producing oxygen, binding dusty soil, and creating a first layer for essential, more complex crops. 

These remarkable results have heightened concerns about planetary protection. The ease with which the sporophytes endured space conditions has caused scientists to question the unforeseen consequences of unintentionally contaminating other planets with Earth’s organisms. As humanity advances towards inhabiting other planets, the role of strict scientific regulations and precautions becomes ever more important. 

The adaptability of these sporophytes reveals both the opportunities and risks that come with humanity’s efforts to expand beyond Earth, offering a potential building block for future colonies while highlighting the critical need for planetary safeguards. 

(ABC News, Phys Org, ScienceDaily, Science News)