Mosses are among Earth’s great terraformers, turning barren rock into fertile soil, and now a team of scientists is proposing that these non-vascular plants can do the same on Mars.
Either we should introducing life from Earth to our red neighbor is another question – we don’t have a great track record with it on our own planet.
But if Deciding that it’s worth tinkering with Martian soil to create a second home for us Earthlings, ecologist Xiaoshuang Li and colleagues at the Chinese Academy of Sciences have a candidate they think should do the trick.
Earth’s surface was once extremely inhospitable to life, but that didn’t stop a group of organisms called bryophytes—which today include mosses, liverworts, and hornworts—from breaking out of the fertile safety of the oceans in search of new horizons.
The success of these earth pioneers depended on their ability to use and digest the nutrients that seep from or flow through the rock, while surviving utterly hostile conditions that would turn other living things to dust. But as they spread across Earth’s rocky border, they created soils that paved the way for other less hardy life forms to gradually set foot on dry land.
This genetic knack continues to serve mosses around the world, and scientists believe we could use their innate talent to colonize Mars and lay the groundwork for other less resilient life forms, such as crops.
Unlike the luscious forest mosses you might imagine, who have it pretty easy compared to their ancestors, Syntrichia caninervis she is determined to promote a very modest way of life. It thrives in the deserts of China and the USA, along with the ice mountains of the Pamirs, Tibet, the Middle East, Antarctica and the circumpolar regions.
The Gurbantunggut Desert in northwestern China is a center for S. caninerviswhich grows more densely here than anywhere else in the world, despite temperatures ranging from −40 °C to 65 °C (−40 °F to 149 °F) and a relative humidity that drops to 1.4 percent.
Li and colleagues tested this moss—and pushed S. caninervis It is not easy to break out of his extremely wide comfort zone.
In the laboratory, they tested the plant’s responses and recovery from extreme dehydration, prolonged freezing (-80 °C for 3 or 5 years and -196 °C for 15 or 30 days), radiation (at doses of 500 to 16,000 Gy) and conditions similar to Mars at the Planetary Atmosphere Simulation Facility (PASF) of the Chinese Academy of Sciences.
In the Mars simulation, the plants were subjected to a pressure of around 650 pascals (Pa), similar to 680–790 Pa on Mars. The temperature was -60 °C at night and 20 °C during the day, corresponding to conditions on Mars in the equatorial to mid-latitude regions. They also simulated atmospheric gas composition and ultraviolet radiation levels to approximate those on Mars.
Dehydration was pro S. caninervis, a walk in the park. And he shrugged in the extreme cold. All frozen plants regenerated after thawing, with plants that were dehydrated before freezing recovering much faster than their soaked counterparts.
Faced with 50 Gy of radiation that would kill humans, S. caninervis he didn’t bat an eyelid. At 500 Gy, her growth even seemed to accelerate.
Mosses that were dehydrated and then exposed to Mars-like conditions could behave as if it had never happened after only 30 days of recovery. Their hydrated counterparts took a bit longer to recover, but still lived to tell the tale.
“Although we still have a long way to go to create self-sustaining habitats on other planets, we have shown great potential S. caninervis as a pioneer plant for growth on Mars,” the researchers write.
“Looking to the future, we expect that this promising moss could be carried to Mars or the Moon to further test the possibility of plant colonization and growth in space.”
Even if moss on Mars turns out to be a terrible idea, the fact is S. caninervis able to turn completely parched land into “living skin” even after surviving such extreme conditions offers some hope for life on our own planet, which seems to be more resilient than we sometimes give it credit for.
This research was published in Innovation.