This moss grew from a spore exposed to space for nine months
Tomomichi Fujita
On 4 March 2022, a fascinating experiment took place outside the International Space Station. Astronauts carefully placed 20,000 moss spores in the harsh environment of space, exposing them to the challenges of the cosmos for 283 days. Upon their return to Earth on a SpaceX capsule, scientists embarked on a mission to germinate these resilient spores – and to everyone’s surprise, they succeeded.
Mosses, some of the earliest terrestrial plants, are renowned for their ability to thrive in extreme environments such as Antarctica, volcanic regions, and deserts. Tomomichi Fujita from Hokkaido University in Japan, part of the research team, explains that the idea behind the experiment was to investigate whether moss spores could withstand the harsh conditions of outer space.
While previous studies have simulated the effects of space conditions on various plant species, this experiment marked the first time researchers tested the resilience of a moss species, specifically Physcomitrium patens, to real space conditions. The results were astounding.
Despite the challenges of vacuum, extreme temperatures, microgravity, UV radiation, and cosmic rays, over 80% of the moss spores exposed to these conditions successfully germinated into healthy plants. The team even speculated that some spores could remain viable in space for up to 15 years, highlighting the remarkable adaptability of these tiny life forms.
Fujita describes the moment of opening the samples as unlocking a biological time capsule, revealing life that had not only survived the void of space but had returned to Earth fully functional. Prior to the space deployment, researchers had tested other parts of the moss in simulated conditions, finding that only the spores could withstand the array of space stresses simultaneously.
The unique structure of spores, with multiple layers of protective walls, seems to act as passive shielding against space stressors. Fujita likens these spores to their own spacecraft, suggesting that this adaptive feature may have evolved to help mosses survive the harsh conditions of early land environments millions of years ago.
While this research does not confirm the existence of extraterrestrial life, it emphasizes the resilience and adaptability of terrestrial life forms. David Eldridge from the University of New South Wales in Sydney highlights that the true test will be to observe whether these moss spores can not only germinate on Earth but also in space, demonstrating their ability to reproduce in extraterrestrial environments.
The findings from this groundbreaking experiment suggest that life, once established, can endure and adapt to even the most extreme conditions, challenging our perceptions of the limits of life on Earth and beyond.
