Recent landing of Perseverance has given idea to NASA for survival of fungus and other microorganisms. When we talked about the possibility of emigrating to Mars, contemplating the situation and what could happen in detail, we raised the possibility that our microorganisms (the terrestrial ones) had already reached Mars despite the sterilization processes of the vehicles. But beyond the accidental ones, those that did reach a theoretically equivalent environment are those of the MARSBOx experiment, of which the results have now been published.
The MARSBOx experiment ( Microbes in Atmosphere for Radiation, Survival, and Biological Outcomes Experiment ) began in 2019, being a collaboration of researchers from NASA and the German Aerospace Center. Using a balloon, a sample of fungi and bacteria was sent into the stratosphere to see the potential survival of the microorganisms in the most Martian conditions possible.
Looking for Martian corners on Earth
The experiment’s proposal is based, as the researchers explain in their work, on the fact that in the stratosphere (specifically at an altitude of 38 kilometers) ** the radiation levels are equivalent to those found on the surface of Mars **. Since sending a probe here is much easier and cheaper than sending something to the Red Planet (in addition, we now have Perseverance there, they decided to study what happened to a handful of microscopic beings under those conditions.
We know that there are microorganisms that resist completely extreme conditions, be it high temperatures (thermophilic bacteria), high concentrations of salt (extreme halophiles) or even radiation (such as Deinococcus radiodurans ), collectively designated by the name of Extremophiles. In fact, on the International Space Station they have already verified that there are bacteria that can survive for years in it.
What they wanted to check this time is the resistance to ultraviolet radiation (about 1,148 kJ / m²) of spores of the fungus Aspergillus niger and bacteria of the species Salinisphaera shabanensis, Staphylococcus capitis subsp. capitis and Buttiauxella spp. . As one might think, spores are among the most resistant forms of life (precisely, they are structures “designed” to withstand the worst conditions and for life to develop when they are favorable) together with the bacteria S. shabanensis, supporting S. capitis subsp. capitis only under certain conditions of the experiment and with the total inactivation of Buttiauxella sp..
What they deduced is that the spores could be reactivated upon returning to Earth (or to a favorable environment). For their part, resistant microorganisms could temporarily endure on the surface of Mars, as in the case of S. capitis subsp. capitis, a bacterium associated with human skin.
Hence, they conclude that spores are potential candidates to be one of the most polluting life forms for our arrival on Mars, although more experiments would still need to be done. Katharina Siems added that these experiments also seek to deduce the survival of the species of microorganisms associated with human beings in the manned missions that are already being planned, because they are symbiosis that we need in our survival (for example, in digestion).
This experiment complements previous ones, such as the one we already saw with the Rio Tinto cyanobacteria, also very resistant organisms. According to Siems, the idea is that with all investigations, useful microorganisms are also found, thinking about the day that it may be necessary to create food or other materials for survival on Mars, as has been investigated in the ISS for years.