Plant Could Help Terraform Mars

With space exploration on the rise, colonizing Mars is becoming an increasingly real prospect. However, for humans to settle on the Red Planet, it is imperative to transform its harsh environment into a viable habitat. One solution could lie in growing plants that can survive Martian conditions and contribute to the production of oxygen. After alfalfa and one GMO rice developed for Martian soila recent study from the Chinese Academy of Sciences sheds light on the moss Syntrichia caninervisanother plant species capable of withstanding the extreme conditions of Mars.

A survivalist plant

Mosses are generally pioneer plants that have evolved to survive in extreme environments and S. caninervis is no exception. You’ll find it primarily in the biological soil crusts (BSCs) of cold deserts. It’s particularly resistant to drought, intense cold, and radiation, making it an ideal candidate for the harsh conditions of Mars. To test this hypothesis, researchers recently subjected the plant to conditions that simulate those on Mars. To do this, they first dehydrated the specimens extremely, then rehydrated them. The results were impressive: the moss is said to have resumed normal physiological functions in just a few seconds. Then the plants were exposed to extremely low temperatures, stored in a freezer at -80°C for five years or in liquid nitrogen (-196°C) for a month. Even under these conditions, the mosses reportedly showed a remarkable capacity for regeneration with a survival rate close to 95%.
Global distribution and different states of the Earth‘s crust of S.caninervis. Credits: Xiaoshuang Li et al., The Innovation, 2024

Resistance to radiation and atmospheric conditions of Mars

In addition to dehydration and cold, Martian plants will also have to cope with radiation levels far higher than those on Earth. As part of this work, the researchers therefore exposed S. caninervis at radiation doses ranging from 500 to 16,000 grays (Gy). The results revealed that plants could not only survive moderate doses of radiation (up to 1,000 Gy), but also regenerate more quickly than control plants. However, at higher doses, regeneration was slower and survival rates fell to about 70% after 60 days of recovery. Despite this, the resistance of S. caninervis radiation is remarkable compared to that of humans who can only withstand doses of up to 50 Gy. Finally, the researchers subjected the plants to a simulation of Mars’ atmospheric conditions, including gas composition and temperature fluctuations. The dehydrated mosses showed a complete recovery after thirty days, while hydrated mosses also survived, but with slower regeneration. These results once again highlight the potential of S. caninervis to survive and even thrive in Mars’ harsh environment. While much work remains to be done to transform Mars into a self-sustaining habitat for humans, this study offers a glimmer of hope. The researchers conclude that S. caninervis could play a crucial role as a pioneer plant in the terraforming of Mars. In addition to produce oxygenthese foams could stabilize the Martian soil and participate in the planet’s biogeochemical cycles. The next steps will be to test this promising foam directly on Mars or on the Moon to verify its colonization and growth capabilities in space. If these tests are conclusive, S. caninervis could well become a key part of our interplanetary future, ushering in a new era of space exploration and human colonization. The paper is published in the journal The Innovation.