Tiny plants endure radiation and vacuum

Japanese scientists have discovered that spores from a hardy moss species survived months of exposure outside the International Space Station. The samples were subjected to radiation, extreme temperature swings and near-vacuum conditions. After returning to Earth, a portion of the spores successfully germinated, surprising researchers and expanding theories about how resilient plant life can be beyond Earth’s atmosphere.

Moss is an ideal test subject because it can enter a dormant state when water is unavailable. Scientists compared the space-exposed samples with those kept under normal conditions and found evidence of DNA damage, but also of repair mechanisms that allowed some spores to recover and grow. The findings may inform future plans for lunar and Martian greenhouses, where plants could contribute to air recycling and food production.

Astrobiology implications

The results add momentum to discussions about whether life could travel between planets on rocks or dust ejected by impacts. While the experiment does not prove panspermia, it shows that multicellular plant structures can endure harsher conditions than previously assumed. Japan’s space agency plans longer tests with seeds, lichens and other extremophiles to build a better understanding of biological limits in space.

For the public, the research offers a striking image: tiny green spores surviving months at the edge of space, then springing back to life in a dish. Scientists say it is a reminder that even familiar organisms can behave unexpectedly when removed from Earth’s protective atmosphere.