Moss Spores Demonstrate Remarkable Resilience, Surviving Years in Space
Table of Contents
A groundbreaking new study reveals that spores from a common moss species, Physcomitrium patens, can survive for extended periods in the harsh habitat of space, offering a potential pathway for establishing life support systems on the Moon and Mars. The research, published online November 20, 2025, in the journal iScience, demonstrates that over 80% of these spores remained viable after nine months exposed to the exterior of the International Space Station (ISS).
As Earth faces increasing environmental challenges, the search for life’s potential beyond our planet has intensified. Understanding how terrestrial organisms respond to extreme conditions is paramount to expanding humanity’s reach into the cosmos. This latest research offers a compelling glimpse into the remarkable adaptability of life at the cellular level.
The Experiment:
“Extreme temperature fluctuations, and microgravity, would cause far greater damage than any single stress alone,” explained a researcher involved in the study. The results were striking. While juvenile moss and brood cells struggled to survive, the sporophytes exhibited exceptional resilience.
Spores: The Champions of Space Survival
the study revealed that UV radiation posed the most notable threat to survival. However, the encased spores demonstrated an astounding 1,000-fold increase in tolerance to UV radiation compared to the other moss structures. They also withstood exposure to temperatures as low as -196 degrees Celsius for over a week and as high as 55 degrees Celsius for a month.
Scientists believe the spore’s protective outer layer plays a crucial role in its survival. This structure absorbs harmful UV radiation and provides a physical and chemical barrier against damage.This adaptation likely stems from the evolutionary history of bryophytes – the group of plants to which mosses belong – which transitioned from aquatic to terrestrial life approximately 500 million years ago and endured numerous mass extinction events.
From ISS to Lab: A Successful Return
In March 2022, hundreds of Physcomitrium patens sporophytes were launched to the ISS aboard the Cygnus NG-17 spacecraft. Astronauts attached the samples to the exterior of the station, exposing them to the full spectrum of space conditions for 283 days. The samples were then returned to Earth on SpaceX CRS-16 in January 2023 for analysis.
“We expected almost zero survival, but the result was the opposite: most of the spores survived,” saeid a lead researcher. “We were genuinely astonished by the extraordinary durability of these tiny plant cells.” over 80% of the spores survived the journey,and nearly 90% of the remaining spores were able to germinate upon their return to the lab. Chlorophyll levels remained largely unaffected, with only a minor 20% reduction in chlorophyll a – a compound sensitive to changes in light.
Predicting Long-Term survival and Future Implications
Using data collected before and after the space expedition, the research team developed a mathematical model to estimate the potential long-term survival of the spores. Their calculations suggest that the encased spores could potentially survive in space for up to 5,600 days – approximately 15 years. However, researchers caution that this is a preliminary estimate and requires further validation with a larger dataset.
“This study demonstrates the astonishing resilience of life that originated on Earth,” a researcher stated. The findings open exciting possibilities for constructing self-sustaining ecosystems in extraterrestrial environments, paving the way for future human settlements on the Moon and Mars.”Ultimately, we hope this work opens a new frontier toward constructing ecosystems in extraterrestrial environments such as the Moon and Mars,” the researcher concluded. “I hope that our moss research will serve as a starting point.”
