Scientists in China say a desert moss commonly found on Earth can survive the harsh conditions of Mars. Future astronauts could use it to grow other plants.
The post This desert moss could grow on Mars, no greenhouse needed first appeared on EarthSky.
Mars’ surface is extremely dry, cold and subject to strong radiation from the sun. It’s so harsh that even lowly lichens and similar organisms would have a difficult time surviving there. But on June 30, 2024, The Guardian said scientists in China have found a species of moss that can withstand Mars-like conditions. That moss – called Syntrichia caninervis – could not only survive, but future astronauts could grow it right in the Martian ground without needing a greenhouse. The moss could also help other plants grow as well.
The researchers published their peer-reviewed findings in the journal The Innovation on July 1, 2024.
Syntrichia caninervis is a desert moss that lives all over the world. It’s common in extreme desert environments. It can be found in China, Mongolia, Siberia, central and southwestern Asia, Europe, North America and even Antarctica.
Syntrichia caninervis is also known as steppe screw moss. Instead of roots, it uses tiny hairs to collect moisture from dew, fog, snow and rain. It has a well-known ability for surviving drought conditions.
If astronauts ever do stay on Mars and build habitats, then they’ll need to be able to grow their own plants. Typically, they would use greenhouses. But the Chinese scientists wanted to see if any plants could grow right in the Martian soil with no greenhouse needed.
With Mars’ extreme conditions, only the most primitive kinds of plants might be able to survive, such as moss. With this in mind, the researchers used the desert moss Syntrichia caninervis. The new study was the first to use whole plants for such Mars experiments. And unlike most other experiments, it focused on growing the plants directly in simulated Martian soil instead of in greenhouses.
So, would it actually work on Mars? The desert moss itself wouldn’t be good as food, but it has other uses. Stuart McDaniel is a moss expert at the University of Florida. He told The Guardian:
Cultivating terrestrial plants is an important part of any long-term space mission because plants efficiently turn carbon dioxide and water into oxygen and carbohydrates, essentially the air and food that humans need to survive. Desert moss is not edible, but it could provide other important services in space.
Research scientist Agata Zupanska at the SETI Institute added:
Otherwise, moss is not tasty and does not make a great addition to the salad.
And so while the moss itself isn’t edible, it could be used to help other plants grow, the researchers said.
The Syntrichia caninervis moss not only survived in the experiments, it basically thrived. It quickly regenerated after being almost completely dehydrated. Incredibly, it was able to regenerate after five years at -112 Fahrenheit (-80 C) and 30 days at -320 F (-196 C).
In addition, the moss survived doses of gamma-ray radiation of up to 500 Gy (units of ionizing radiation). For humans, the lethal dose is about 50 Gy.
That’s good news, but the researchers wanted to simulate the Martian conditions even more precisely. They replicated the pressures, temperatures, gases and UV radiation on Mars. Even then, the moss survived and continued to regenerate normally, after seven days. Notably, samples of moss that were dried out before the experiments did better than the other samples. McDaniel said:
This paper is exciting because it shows that desert moss survives short exposures to some of the stresses that are likely to be found on a trip to Mars, including very high levels of radiation, very cold temperatures, and very low oxygen levels.
And as the paper noted:
Looking to the future, we expect that this promising moss could be brought to Mars or the moon to further test the possibility of plant colonization and growth in outer space.
Being able to grow moss on Mars is an exciting possibility, but the researchers caution that this work is still preliminary, and the current tests had limitations. As McDaniel said in The Guardian:
These experiments represent an important first step, but they do not show that the moss could be a significant source of oxygen under Martian conditions, nor do they show that the desert moss could reproduce and proliferate in the Martian context.
Zupanska added:
In my opinion, we are getting close to growing plants in extraterrestrial greenhouses, and moss certainly has a place in those. Implying that moss, or any other pioneering species, is ready to terraform Mars, or any other outer planet, is an exaggeration.
Also, while replicating Martian conditions overall, the tests didn’t use simulated Martian soil, as Wieger Wamelink at Wageningen University in The Netherlands noted:
The mosses were treated under Mars circumstances for a maximum of several days and then regrown under Earth conditions on sand. This, of course, does not show at all that they can grow under Mars conditions.
So while there is still much work to be done, these tests are an important step toward one day being able to grow plants on Mars for human habitation. Edward Guinan at Villanova University in Pennsylvania agreed with that assessment, saying:
This extremotolerant moss could be a promising pioneer plant for Mars colonization. We have a long way to go. But this lowly desert moss offers hope for making small portions of Mars habitable for humankind in the future.
Bottom line: Scientists in China say a desert moss commonly found on Earth can survive the harsh conditions of Mars. Future astronauts could use it to grow other plants.
Read more: Want to find life on Mars? Look deep underground
Read more: NASA unveils Mars habitat on Earth for a yearlong test
The post This desert moss could grow on Mars, no greenhouse needed first appeared on EarthSky.
