Moss spores survived nearly a year in harsh space conditions, scientists confirm

Scientists Confirm Moss Spores Survived Nearly a Year in Harsh Space Conditions (Representative Image: Canva)

Space may seem silent and distant, yet small life forms can still surprise scientists. A new study has shown that tiny moss spores returned to Earth after nine months outside the International Space Station, still alive and ready to grow.

Moss Spores Survive Space Exposure

Scientists asked how well plant spores endure harsh space conditions. They tested P. patens cells through different reproductive stages. They found that sporophytes held strong under UV light, heat, and freezing. They then placed these samples in a special exposure unit on Japan’s Kibo module. The samples stayed outside the ISS for nine months in 2022. They were later brought back to Earth for further checks.

Researchers reported their results in the journal iScience on 20 November. They found that over 80% of the spores survived the journey. Many spores also germinated normally, said Tomomichi Fujita from Hokkaido University. His team created a model showing spores may survive in space for nearly 5,600 days. That equals almost 15 years in open space.

Why Moss Survived So Well

The team asked what protected the moss during space exposure. They found that space vacuum and microgravity caused little harm. Harsh temperature shifts also made limited impact on return. Spores exposed to intense UV light showed more damage. They lost key pigments needed for photosynthesis, including chlorophyll a. This loss slowed later growth on Earth.

Researchers noted that P. patens performed better than other plants tested in similar work. Some spores still suffered damage, yet most endured difficult conditions. Fujita said their protective shell likely shields them from dehydration and UV rays. The defence may have helped early mosses spread across new land habitats.

Future Space Ecosystems

Experts asked what these results mean for life beyond Earth. Fujita said the spores’ strong survival could support future space ecosystems. He plans to test more species soon. The team hopes to understand how other cells withstand extreme space environments.