November 19, 2025
2 min read
Meet the Weird and Wonderful Life-forms That Can Survive in Space
The moss Physcomitrium patens joins tardigrades and thale-cress as a species that has survived in space
A reddish-brown sporophyte can be seen at the top center of a leafy gametophore. This capsule contains numerous spores inside. Mature sporophytes like these were individually collected and used as samples for the space exposure experiment conducted on the exposure facility of the International Space Station.
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From deep-sea hydrothermal vents to freezing glaciers, there are plenty of harsh environments on Earth. But they’re nothing compared with outer space.
There are, however, a growing list of species, such as tardigrades and certain flowering plants, that can survive in that cold vacuum. The most recent addition is a type of moss, scientists at Hokkaido University in Japan and their colleagues recently reported in iScience.
“The fact that another major group of terrestrial life can survive in space, as far as physical findings, is cool,” says University of Florida space biology expert Robert Ferl, who was not involved in the study. “Terrestrial life may not be limited to the Earth.”
Space is a tough place to survive. It lacks air and has extreme amounts of ultraviolet radiation that can damage DNA. And its temperatures range from freezing to extreme heat. But mosses are resilient. They were one of the first plants to adapt to land when such life started transitioning out of the water about 500 million years ago.
The Hokkaido University research team studied Physcomitrium patens, a species of moss that is typically found around pools of water in temperate parts of the world, including Europe, North America and East Asia. They compared the tolerance of three different stages of the plant: the protonemata, or the moss’s juvenile stage; the brood cells, specialized cells that emerge in stressful conditions; and the plant’s reproductive spores, which are produced in a tough capsule known as the sporangium.
The researchers simulated space conditions by exposing the three tissues to UV radiation and freezing and high temperatures. For each simulation, the spores were always more resilient than the other two plant parts. “[The spores] are very strong, more than we expected,” says plant biologist and study co-author Tomomichi Fujita.
To further test the spores, they were placed on a platform outside of the International Space Station from early March to late December 2022. After they were brought back to Earth, they were grown on a petri dish, and more than 80 percent of the spores germinated.
“The next question is: Why?” Fujita says. “We don’t know the reason why [the spores] are so strong,” but it may be because they are dormant in space. Additionally, although more spores germinated than the team expected, their growth rate was delayed.
Next, the researchers want to know the genes involved in the spores’ tolerance to space to see if there was any UV-induced DNA damage.
Studying how terrestrial life, such as moss, flowers and microorganisms, fare in space clues scientists into how future forms of life could be sustained in the stars. Though it’s a far cry from reality, knowing this could help expand human habitats beyond Earth.
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