Can life from Earth survive on Mars? Some microbes may, posing new challenges to space travel: Study
Understanding the endurance of microbes to space travel is critical for the success of future missions. When searching for extra-terrestrial life, scientists need to be sure that anything they discover has not just traveled with them from Earth. A new analysis sheds some light on this and reveals that some microbes on Earth could temporarily survive on the surface of Mars.
The research team from NASA and German Aerospace Center tested the endurance of microorganisms to Martian conditions by launching them into the Earth’s stratosphere, where key conditions are similar to those on the Red Planet. Their findings show that “microbial hitchhikers like the black mold fungus” can potentially survive on Mars, raising new challenges and possibilities for future exploration of the Red Planet.
“We successfully tested a new way of exposing bacteria and fungi to Mars-like conditions by using a scientific balloon to fly our experimental equipment up to Earth’s stratosphere. Some microbes, in particular spores from the black mold fungus, were able to survive the trip, even when exposed to very high UV radiation,” says Marta Filipa Cortesão, joint first author of this study from the German Aerospace Center, Cologne, Germany.
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Microorganisms are closely-connected to us, our body, our food, our environment, so it is impossible to rule them out of space travel. According to the experts, the work paves the way for understanding the threat of microbes to space missions, as well as the opportunities for resource independence from Earth. The findings have been published in Frontiers in Microbiology.
“With crewed long-term missions to Mars, we need to know how human-associated microorganisms would survive on the Red Planet, as some may pose a health risk to astronauts. In addition, some microbes could be invaluable for space exploration. They could help us produce food and material supplies independently from Earth, which will be crucial when far away from home,” explains joint first author Katharina Siems, also based at the German Aerospace Center.
The experiment
Many key characteristics of the environment at the Martian surface cannot be found or easily replicated at the surface of our planet, however, above the ozone layer in Earth's middle stratosphere the conditions are remarkably similar.
Accordingly, the authors launched the microbes into the stratosphere inside the Microbes in Atmosphere for Radiation, Survival, and Biological Outcomes experiment (MARSBOx) payload. It was kept at Martian pressure and filled with an artificial Martian atmosphere throughout the mission. The aim was to determine their potential use and threats to space travel.
“Whether terrestrial life can withstand the martian environment is of paramount interest for planetary protection measures and space exploration. To understand microbial survival potential in Mars-like conditions, several fungal and bacterial samples were launched in September 2019 on a large NASA scientific balloon flight to the middle stratosphere (approximately 38 km altitude) where radiation levels resembled values at the equatorial Mars surface,” write authors. They add, “Fungal spores of Aspergillus niger and bacterial cells of Salinisphaera shabanensis, Staphylococcus capitis subsp. capitis, and Buttiauxella sp. MASE-IM-9 were launched inside the MARSBOx payload filled with an artificial martian atmosphere and pressure throughout the mission profile.”
The box had two sample layers, with the bottom layer shielded from radiation. This allowed the scientists to separate the effects of radiation from the other tested conditions: desiccation, atmosphere, and temperature fluctuation during the flight. The top layer samples were exposed to more than a thousand times more UV radiation than levels that can cause sunburn on the skin.
“While not all the microbes survived the trip, one previously detected on the International Space Station, the black mold Aspergillus niger, could be revived after it returned home,” concludes Siems.