The Moss That Could Transform Mars
Mars may be the most promising planet for establishing a human extraterrestrial colony. However, the disadvantages of Mars are also obvious. Firstly, Mars is mainly composed of rocky deserts, suffers from fatal radiation, and has harsh temperature conditions. And so far, it seems that scientists have not yet found any detectable life on Mars nor any nutrients that life depends on.
Despite the harsh environment of Mars, it has not stopped the efforts of scientists. Scientists dream of finding a new way to plant Earth crops on this red planet. Among them, a controversial method is to find a certain type of pioneer species that can survive in the harsh soil environment and climate conditions of Mars, let these species take the lead to create an Earth-like environment on Mars, so as to lay the foundation for the survival of other lives - this is also known as terraforming Mars.
After humans colonize Mars and the moon, the resources obtained on the planet will be extremely limited. All resources including energy, physical space, water, and nutrients will be restricted. Rebecca Gonçalves, a research scientist and astrobiologist at the Brazilian Space Agency (AEB), explained.
Facts have proved that the wall moss has the ability to resist pressure comparable to those superheroes in comics.
A new study published in The Innovation杂质 shows that the most likely candidate to take on the terraforming Mars mission is a moss that dominates in many arid regions of the world and is widely distributed in the Gurbantunggut Desert in China, the Tengger Desert, the Mojave Desert in the United States, as well as in Tibet, the Middle East, and mountainous areas in Antarctica. This moss is called Syntrichia caninervis and can survive in the most extreme environments on Earth, and these environments are fatal to most organisms.
Take the Gurbantunggut Desert in northwest China as an example - it is one of the areas with the most concentrated moss distribution in the world. The desert temperature varies from minus 40 degrees Celsius to plus 65 degrees Celsius, and the relative humidity is as low as 1.4%. (In contrast, the average relative humidity in the Palm Springs desert area in California is between 28% and 48%.)
The authors of the new study involved wanted to test the survival ability of moss in an environment similar to that of Mars. So they conducted various stress tests on the moss in the laboratory. First, they dried some moss samples to a state of losing 98% of their water, and some were irradiated with gamma rays. This kind of radiation can kill a human within an hour or cause serious damage to most plants. Some samples were stored in a freezer at minus 80 degrees Celsius for five years, and some samples were placed in a liquid nitrogen storage tank at minus 196 degrees Celsius for 15 to 30 days. Finally, they placed these samples in a simulated Mars environment, which combines the above-mentioned multiple extreme conditions and the extremely low oxygen concentration in the thin Martian atmosphere.
Facts have proved that Syntrichia caninervis has the ability to resist pressure comparable to that of the superheroes in comics. In the wild, when the moss loses 98% of its water, it will become completely black, and the same is true in the laboratory. However, only two seconds after rehydrating the moss, the moss returns to green and quickly restores its photosynthesis ability. Similarly, after taking the moss out of the freezer or liquid nitrogen storage tank for a period of time, the moss can recover quickly, and the growth rate is close to that of the untreated control group. If the radiation level is much higher than the level that can kill a human within an hour, it will actually promote the growth of the plant. However, when the radiation reaches a certain threshold (that is, 8 to 16 times the radiation dose that can kill a human within an hour), the impact of radiation on the plant will be more harmful than beneficial.
The author of the article believes that the research shows that Syntrichia caninervis may be one of the best candidates for terraforming Mars. The researchers said that moss helps to produce oxygen, sequester carbon, and improve soil fertility, which helps to promote common atmospheric, geological, and ecological processes on Earth. After all, the moss cover is the earliest stage of the formation of the biological soil crust and is one of the first organisms to settle on Earth. (Compared with algal and lichen crusts, moss crusts contain more biomass and are better at fixing carbon and retaining moisture in the desert soil, thus helping to stabilize the soil.)
Perhaps humans really need a super plant to turn Mars into an escape route for Earth, and make Mars a habitable planet suitable for humans, animals, and plants to live on. Of course, what we cannot predict is what unexpected consequences human intervention will trigger on Mars or other planets. This issue is of philosophical significance. Many people are thinking about how to immigrate to Mars morally while protecting the Mars environment. Gonçalves said. She recently published one of her studies in the journal Annals of the New York Academy of Sciences (PLOS One), exploring the potential benefits of using the ancient agricultural technique of intercropping to grow food on Mars.
Author: Tom Metcalfe
Translation: Bian Ying
Review: Xiao Cong
Original Link: The Moss That Could Terraform Mars
This article is from the WeChat public account: WeChat public account (ID: null), by Tom Metcalfe