Hokkaido University Moss Survives 9 Months of Direct Space Exposure
- MM24 News Desk
- 11 hours ago
- 3 min read
Researchers from Japan's Hokkaido University have revealed that moss spores endured 283 days on the exterior of the International Space Station, with over 80% surviving the vacuum, cosmic radiation, and extreme temperature swings of space.
The study, led by Professor Tomomichi Fujita, demonstrates for the first time that an early land plant can survive long-term exposure to the harsh elements of space and return to Earth capable of normal reproduction.
Imagine a plant so tough it can handle the absolute vacuum of space, a place where most life, including humans, would perish in seconds. This isn't science fiction; it’s the reality for a humble moss called Physcomitrium patens. In a groundbreaking experiment, this moss has proven that life from Earth possesses a cellular hardiness we are only beginning to understand.
The concept for this extraterrestrial test came from Professor Tomomichi Fujita of the Graduate School of Science at Hokkaido University, who was studying how plants evolved to conquer land. He was struck by moss's incredible ability to thrive in Earth's most punishing environments, from Antarctic tundras to scorching deserts. "I began to wonder: could this small yet remarkably robust plant also survive in space?" Fujita explained,according to the team's publication in the journal iScience.
To find an answer, his team first recreated space on Earth. They subjected different parts of the moss to simulated space conditions, including intense UV radiation, vacuum, and wild temperature swings. They tested three structures: juvenile moss, stress-resistant brood cells, and sporophytes, which are capsules that encase spores.
The results were clear. While the juvenile moss perished, the encased spores were the champions of resilience. The sporophytes exhibited ~1,000x more tolerance to UV radiation than other moss cells. They also survived a week at a frigid -196°C and a month in 55°C heat.
The researchers suggest the spore's protective casing acts as a biological shield, absorbing harmful UV radiation and providing a physical and chemical buffer. This is likely an ancient evolutionary adaptation that helped mosses' ancestors, the bryophytes, transition from water to land 500 million years ago and survive multiple mass extinction events since. But could this earthly armor hold up in real space? There was only one way to find out.
In March 2022, the team sent hundreds of these moss sporophytes to the International Space Station (ISS) aboard the Cygnus NG-17 spacecraft. Astronauts then mounted the samples on the outside of the station, leaving them completely exposed to the space environment for 283 days. The moss hitched a ride back to Earth in January 2023 on SpaceX CRS-16 for analysis.
The team expected the worst, but the result was stunning. "We expected almost zero survival, but the result was the opposite: most of the spores survived," Fujita stated, as reported by iScience. "We were genuinely astonished by the extraordinary durability of these tiny plant cells."
The data confirmed their astonishment. Over 80% of the spores were still alive after their intergalactic journey. Even more impressive, nearly all of the surviving spores were able to germinate and grow back in the lab. Analysis showed their chlorophyll levels were largely normal, with only a minor reduction in one compound that didn't affect their overall health.
Curious about the limits of this survival, the team used their data to create a mathematical model. They made a staggering prediction: these encased moss spores could potentially survive in space for up to 5,600 days, which is roughly 15 years. The researchers caution that this is a preliminary estimate, but it highlights an incredible potential for long-term survivability.
This study does more than just catalog an extreme organism; it opens a new chapter in astrobiology and the future of space exploration. The ultimate goal, Fujita says, is to use this knowledge to advance research into creating sustainable ecosystems beyond Earth. "Ultimately, we hope this work opens a new frontier toward constructing ecosystems in extraterrestrial environments such as the Moon and Mars," he said. "I hope that our moss research will serve as a starting point."
Comments