The desert moss Syntrichiacaninervis, which can survive extreme cold, radiation and Mars-like conditions, could hold the key to colonizing Mars, potentially supporting sustainable extraterrestrial habitats. Syntrichiacaninervis has great potential for colonizing Mars due to its extraordinary ability to adapt to extreme conditions that would normally be fatal to most life forms.

The desert moss Syntrichiacaninervis has been shown to be able to survive extreme environmental conditions, making it possible to become a pioneer plant for colonizing Mars. Its adaptability to freezing temperatures, high radiation and simulated Martian conditions highlights its suitability for extraterrestrial habitats. Image credit: SheriHagwood, courtesy USDA-NRCS PLANTS database

The moss can also withstand temperatures as low as minus 196 degrees Celsius, high levels of gamma-ray radiation, and a simulated Martian environment with these combined stresses, the researchers report in the journal The Innovation. In all cases, prior dehydration appeared to enhance the moss's ability to withstand these harsh conditions.

"Our study shows that its environmental adaptability is superior to that of some highly stress-tolerant microorganisms and late-type organisms," wrote the researchers, including ecologists Zhang Daoyuan and Zhang Yuanming and botanist Kuang Tingyun of the Chinese Academy of Sciences. "S. caninervis is a promising candidate pioneer plant for extra-colonial environments, laying the foundation for establishing biologically sustainable human habitats beyond Earth." "

A handful of previous studies have tested the ability of microorganisms, algae, lichens and plant spores to withstand the extreme environments of outer space or Mars, but this is the first time whole plants have been tested.

Syntrichiacaninervis is a common moss species widely distributed around the world. It grows in extremely extreme desert environments, including Tibet, Antarctica and the Circumpolar Region, and is part of the biological soil crust - a widespread and hardy ground cover common in arid regions. Given the moss's ability to survive extreme environmental conditions, the researchers decided to test its limits in the laboratory.

To test the moss' cold tolerance, the researchers stored the plants at minus 80 degrees Celsius (in an ultra-low temperature freezer) for three and five years, and at minus 196 degrees Celsius (in a liquid nitrogen tank) for 15 and 30 days. In all cases, plants regenerated after thawing, although plants regenerated more slowly than control samples that were dehydrated but not frozen, and plants that were not dehydrated before freezing also regenerated more slowly than plants that were dried and then frozen.

The moss has also shown the ability to survive gamma ray exposure, which would kill most plants, and a dose of 500Gy even appeared to promote plant growth. By comparison, humans suffer severe convulsions and die when exposed to approximately 50Gy of radiation. "Our results indicate that S. caninervis is one of the most radiation-tolerant organisms known," the researchers wrote.

Finally, the researchers used the Chinese Academy of Sciences' Planetary Atmosphere Simulation Facility to test the moss's ability to withstand the Martian environment. The Martian environment in the simulator includes 95% carbon dioxide air, temperatures ranging from -60°C to 20°C, high levels of ultraviolet radiation and low atmospheric pressure. After dry bryophytes were grown under Martian conditions for 1, 2, 3 and 7 days, the regeneration rate reached 100% within 30 days. Hydrated bryophytes that were left in the simulator for just one day also survived, although they regenerated more slowly than dry bryophytes.

"While establishing self-sustaining habitats on other planets is still a long way off, we demonstrated the great potential of S. caninervis as a pioneer plant growing on Mars," the researchers wrote. "Going forward, we hope to bring this promising moss to Mars or the Moon to further examine the possibility of colonizing and growing plants in outer space."

Compiled from /ScitechDaily