Adding a small amount of water brought the moss back to life within seconds and resumed photosynthesis, converting carbon dioxide into the oxygen and carbohydrates essential to human survival on any planet, the researchers wrote.
“It represents a promising candidate as a colonist to facilitate terraforming on Mars … and to drive the atmospheric, geological, and ecological processes necessary for other higher plants and animals.”
The findings caught the attention of astrobiologist Lin Wei of the Institute of Geology and Geophysics in Beijing, who described them as “very interesting and valuable”.
“With a series of scientific experiments, the team has shown that Syntrichia caninervis “Being able to survive in a simulated Mars environment for a week,” said Lin, who was not involved in the research.
The paper’s lead author, Li Xiaoshuang, a cell biologist at the Xinjiang Institute of Ecology and Geography, told the South China Morning Post that she has been studying the “magical” plant for 20 years.
The desert moss was known for its excellent resistance to drought and radiation, she said. “Most plants would die if they lost 30 percent of their cell water. This one survives after complete dehydration.”
Li and her team spent a long time searching for genes in the moss that are resistant to drought. They hoped that this would help other plants grow better in really dry environments. Until they accidentally discovered that the moss also thrives under ice in the winter.
“I got really curious and started putting it in freezers and then in liquid nitrogen tanks,” Li said. “It really stood out as the only plant that had shown such extraordinary resistance to different environmental stressors.”
The research found that the moss could regenerate under normal growing conditions after spending five years at -80 degrees Celsius (-112 Fahrenheit) and 30 days at -196 degrees Celsius (-320.8 Fahrenheit).
Finally, the researchers took some moss samples to a simulation booth at the National Space Science Centre in Beijing to test whether they could withstand conditions similar to those on Mars.
The simulator was preset for an air composition of 95 percent carbon dioxide, a temperature range between -60 and 20 degrees Celsius (-76 and 68 Fahrenheit), and radiation levels similar to those on the surface of Mars.
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China’s Zhu Rong rover discovers evidence of ancient sea on Mars
China’s Zhu Rong rover discovers evidence of ancient sea on Mars
Li and her team found that the dried moss plants fully recovered within 30 days after exposure to Martian conditions for one, two, three, and seven days. Hydrated plants exposed to the simulator for one day also survived, but regenerated more slowly.
According to Li, the team has already planted the moss in a replica of soil found on Mars. “It grew very well and all it needed was water,” she said.
Next, Li and her team will explore opportunities to send moss samples into space for exposure experiments, or even to the surface of the moon or Mars.
“Mosses were the first embryophytes to leave the ocean and colonize land in Earth’s history. We are curious to see if colonization can happen again on Mars,” she said.