This moss survived 9 months outside the ISS, enduring vacuum, UV, and extreme temperature swings, then returned to Earth still viable.
Led by Tomomichi Fujita of Hokkaido University, researchers exposed spores of the moss Physcomitrium patens (spreading earthmoss) on the exterior of the International Space Station for 283 days. They wanted to test whether this ancient plant could withstand the brutal environment of space.
When the samples returned to Earth in early 2023, more than 80 percent of the spores were still alive—and many germinated in the lab. The team was “genuinely astonished” by the survival rate, suggesting that even simple land plants from Earth may be tough enough for future space ecosystems.
How this moss survived 9 months in space?
To know how this moss survived 9 months outside the International Space Station, Researchers have long wondered how life from Earth could persist beyond our planet. Mosses are ancient land plants, and P. patens has been a favorite in labs for decades. By sending its reproductive structures (sporophytes) into space, scientists hoped to learn whether plant life could survive—or even help build ecosystems—in alien settings like the Moon or Mars.
Testing Resistance on Earth First
In relation to knowing how this moss survived 9 months outside the International Space Station and before risking an orbital mission, Fujita’s team simulated space stressors on Earth: vacuum, microgravity-like conditions, high UV radiation, and extreme temperatures. They exposed three moss life stages—juvenile moss, stem cells, and sporophytes—to these conditions. The sporophytes (which contain spores) turned out to be the most resilient.
The Nine-Month Journey Outside the ISS
In March 2022, hundreds of sporophytes were launched aboard Northrop Grumman’s Cygnus NG-17 spacecraft and attached to the Kibō module on the ISS exterior. For 283 days, they faced direct exposure to vacuum, fluctuating temperatures, UV radiation, and microgravity—all without shielding.
Astonishing Survival and Germination
When retrieved in January 2023 via a SpaceX Dragon capsule, more than 80 percent of the moss spores had survived the ordeal. In the lab, around 86 percent germinated, though there was about a 20 percent drop in chlorophyll a. Still, many of the returned moss cells showed healthy growth.
Why It Matters for Space Colonies
This moss survived 9 months outside the International Space Station in space—and that could be more than a quirky fact. It indicates that primitive land plants might be practical building blocks for future space habitats. Moss could help produce oxygen, stabilize soil, or even form the first green layer in extraterrestrial environments.
Modeling Long-Term Survival
Using their data as for knowing how this moss survived 9 months outside the International Space Station, Fujita’s team built a mathematical model projecting that the spores could survive in space for up to 5,600 days (about 15 years) if conditions remain similar to those on the ISS. Though that’s a rough estimate, it suggests a potential for long-term resilience beyond short-term missions.
Conclusion
This moss survived 9 months in space, defying expectations and demonstrating extraordinary durability. By returning to Earth alive and capable of growth, it highlights how life from our planet might support future off-world habitats. These results open a promising chapter for astrobiology—and for building sustainable ecosystems beyond Earth. Explore more cosmology concepts on our YouTube channel—so join NSN Today.
