The two planets may not look very similar, but our stratosphere – a layer of the atmosphere 20 miles above the Earth’s surface – has some qualities in common with Mars. Our home planet Sthe tractosphere has low air pressure and high levels of radiation and is dry and cold – just like the surface of the red planet.
Using MARSBOx, or Atmospheric Microbes for radiation, survival, and the experiment of biological results, scientists at NASA and the German Aerospace Center collaborated to send four types of microbes into the stratosphere on a balloon.
“If a microbe can pirate it up there, above many protective layers of ozone, it might even be able to survive – however short – on a trip to the surface of Mars,” said study co-author David J. Smith. MARSBOx co-principal investigator and researcher at NASA’s Ames Research Center, in a statement.
Microbes or microorganisms, they have an expansive coverage on Earth. It is estimated that there are 1 trillion species of them on our planet. They can also be found living in harsh environments in various extreme conditions.
NASA scientists need to know if these microbes can survive on Mars, while continuing to send robotic explorers to the red planet on behalf of humans. That’s why the mission teams behind these rovers, such as the recently landed Perseverance rover, take the cleaning of these cars very seriously before they are launched to Mars.
To test the likelihood of microbial survival on Mars, the research team placed millions of microbes, including fungal spores and dry, latent bacteria representing four species of microorganisms, on quartz disks. These disks were placed in aluminum boxes designed by study collaborators at the German Aerospace Center.
A mixture of gases similar to those in the Martian atmosphere, which is dominated by carbon dioxide, was pumped into cans. A large science balloon carrying the experiment was launched from Fort Sumner, New Mexico, on September 23, 2019.
Blinds have been used to help protect against microbes from the sun during ascent and descent. But once they reached the Earth’s stratosphere 24 miles up, the shutters opened and exposed them to the harsh radiation there. The microbes were exposed to it for more than five hours, along with negative average temperatures of 20 degrees Fahrenheit.
In the stratosphere, there is a pressure a thousand times lower than we experience at sea level, as well as very dry air.
When the experiment returned to the ground, the scientists determined that two of the four species survived the trip, proving that these two could temporarily withstand the harsh conditions of the Earth’s stratosphere and potentially the Martian surface.
“This research gives us a better understanding of microbes that could persist in environments once thought to be lethal, such as the surface of Mars, and gives us clues on how to avoid inadvertently bringing small hitchhikers with us to destinations outside the world.” ”Said study co-author Ralf Moeller, MARSBOx lead co-investigator and head of the Aerospace Microbiology Research Group at the German Aerospace Center, in a statement.
Surviving species included Staphylococcus capitis and Salinisphaera shabanensis. The first is a bacterium associated with human skin and the second is a bacterium that can be found in deep brine basins.
Aspergillus niger, a fungus used in the production of antibiotics, was dried to send to the experiment and could also be invigorated once it returned from the Earth’s stratosphere.
“The spores in the A. niger fungus are incredibly resistant – to heat, harsh chemicals and other stressors – but no one has ever studied whether they could survive exposure in space or under intense radiation, as we see on Mars,” he said. said co-author of the study, Marta Cortesão, a doctoral student in the Aerospace Microbiology Research Group at the German Aerospace Center, in a statement.
“The fact that, after their MARSBOx flight, we could revive them proves that they are brave enough to resist wherever people go, even outside the planet.”
Aspergillus niger may have sun-like pigmentation or a cellular structure to protect itself.
“This experiment raises a lot of questions about what genetic mechanisms are essential for microbes to survive,” Cortesão said. “Do they carry ancient evolutionary traits that give them the ability to withstand harsh conditions or do adapting to their current environment provide protection for many other environmental challenges?”
Future research could help scientists better determine why these microbes survived. A follow-up flight is planned for MARSBOx in Antarctica, where both the sun’s radiation and the galactic cosmic rays in space are even more like Mars.
“These balloon aerobiology experiments allow us to study microbial resistance in impossible ways in the laboratory,” Smith said. “MARSBOx provides an opportunity to predict the results of survival on Mars and to help set the boundaries of life as we know it.”
In the meantime, these discoveries could help plan future missions to Mars. “The renewed focus on robotic and human exploration on Mars amplifies the need for additional analog studies on Mars in the coming years,” the study authors wrote.
“With long-term manned missions to Mars, we need to know how human-associated microorganisms would survive on the Red Planet, as some could pose a health risk to astronauts,” said study co-leader Katharina Siems, PhD student in -a statement, the Aerospace Microbiology Research Group of the German Aerospace Center.
“In addition, some microbes may be invaluable for space exploration. It could help us produce food and materials independently of the Earth, which will be crucial when we are away from home. Microorganisms are closely related to us; our body, our food, our environment, so it is impossible to exclude them from space travel. “