A new study by NASA and German Aerospace Center has found that some microbes from Earth can temporarily survive on Mars.
The researchers tested the microorganisms’ ability to survive on Mars by launching them into the Earth’s stratosphere, as it closely represents key conditions on the Red Planet. Published in Frontiers in Microbiology, this work paves the way for understanding not only the threat of microbes to space missions, but also the opportunities for resource independence from Earth.
Marta Filipa Cortesão, joint first author of this study from the German Aerospace Center, Cologne, Germany, said: “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 mould fungus, were able to survive the trip, even when exposed to very high UV radiation.”
Space agencies must be conscious of the survival of microbes in space. Joint first author Katharina Siems, also based at the German Aerospace Center, explained: “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.”
Replicating the surface of Mars
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.
The research team launched the microbes into the stratosphere inside the MARSBOx (Microbes in Atmosphere for Radiation, Survival and Biological Outcomes experiment) payload, which was kept at Martian pressure and filled with artificial Martian atmosphere throughout the mission.
The box carried two sample layers, with the bottom layer shielded from radiation. This allowed the researchers 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 our skin.
Siems added: “Microorganisms are closely-connected to us; our body, our food, our environment, so it is impossible to rule them out of space travel. Using good analogies for the Martian environment, such as the MARSBOx balloon mission to the stratosphere, is a really important way to help us explore all the implications of space travel on microbial life and how we can drive this knowledge towards amazing space discoveries.”