Scientists have made a remarkable discovery that could reshape our understanding of life’s resilience beyond Earth. Recent experiments involving moss in space have revealed that these humble plants possess extraordinary survival capabilities, even when exposed to the most extreme conditions imaginable. This breakthrough has significant implications for future space exploration and the potential colonisation of other planets.
The ground-breaking experiment with moss in space
Researchers placed samples of Physcomitrium patens, commonly known as spreading earthmoss, on the exterior of the International Space Station for an extended period. The moss spores remained outside the station for 283 days—approximately nine months—fully exposed to the harsh vacuum of space.
During this time, the samples faced conditions that would destroy most living organisms. They endured extreme temperature fluctuations ranging from blistering heat to freezing cold, intense ultraviolet radiation, and the complete absence of atmospheric pressure.
Astonishing survival rates exceed expectations
When the moss samples returned to Earth, scientists were genuinely stunned by the results. More than 80% of the spores had survived their ordeal in space. Even more remarkably, when researchers attempted to grow these space-travelled spores, approximately 89% of the survivors successfully germinated and developed into healthy moss plants.
Dr Tomomichi Fujita from Hokkaido University, who led the research team, admitted they had “expected almost zero survival.” The resilience demonstrated by these organisms far exceeded scientific predictions, marking a significant milestone in astrobiology research.
Why moss could be crucial for space colonisation
The ability of moss to withstand space conditions isn’t merely a scientific curiosity. These findings have practical implications for humanity’s ambitions beyond Earth. As space agencies plan for long-term missions to the Moon and Mars, understanding which organisms can survive in extraterrestrial environments becomes increasingly important.
Moss could play several vital roles in future space habitats:
- Producing oxygen through photosynthesis in enclosed habitats
- Serving as a foundation for sustainable agricultural systems
- Helping to create soil-like growing mediums for other plants
- Providing psychological benefits through greenery in isolated environments
How researchers tested different moss structures
The research team didn’t limit their investigation to spores alone. They tested various developmental stages of the moss, including juvenile moss structures called protonemata, specialised brood cells, and mature sporophytes that produce spores.
Prior to the space experiment, researchers conducted preliminary tests on Earth. They subjected the moss to simulated space conditions including extreme heat and cold, UV radiation exposure, and low-pressure environments. These ground-based tests helped identify that spores were the most resilient life stage of the moss.
The journey to space and back
The moss samples travelled to the International Space Station aboard a SpaceX cargo mission. Once installed on the exterior of the station, they orbited Earth at approximately 28,000 kilometres per hour, completing roughly 16 orbits daily whilst exposed to the unforgiving space environment.
After their nine-month exposure period, the samples returned to Earth on SpaceX CRS-16 in January 2023. Scientists immediately began cultivation experiments to assess viability and study any changes the space environment might have caused.
What this means for astrobiology
The success of moss in space experiments contributes to our understanding of panspermia—the theory that life could potentially transfer between planets or solar systems. Whilst moss didn’t originate in space, its survival demonstrates that some Earth organisms could theoretically withstand interplanetary journeys.
Additionally, these findings inform the search for life on other worlds. If terrestrial moss can survive such harsh conditions, it’s conceivable that similar organisms could exist or have existed on planets like Mars, which once had more favourable conditions.
Future research directions
Scientists are now investigating the genetic and cellular mechanisms that enabled such remarkable survival. Understanding exactly how moss cells protect themselves from radiation damage and extreme temperatures could help develop better protection for human astronauts on long-duration missions.
Researchers, including experts studying radiation-resistant Antarctic mosses, are comparing different moss species to identify which characteristics contribute most to space survival. This comparative approach may reveal whether other plant species could demonstrate similar resilience.
Conclusion
The discovery that moss in space can survive and thrive after months of extreme exposure represents a significant advance in both astrobiology and practical space exploration. These unassuming plants have proven themselves remarkably hardy, offering hope for developing sustainable life support systems for future lunar bases and Martian colonies. As humanity takes its first steps towards becoming a multi-planetary species, moss may well be amongst our most valuable companions on that journey.
Sources
- Live Science – Scientists put moss on the outside of the International Space Station for 9 months, then kept it growing back on Earth
- NBC News – Moss survived outside space station
