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 tratosphere experiences low air pressure and high levels of radiation, and is dry and cold, similar to the surface of the red planet.
Using MARSBOx, or atmospheric microbes for the experiment of radiation, survival, and biological results, scientists from NASA and the German Aerospace Center collaborated to send four types of microbes into the stratosphere in balloons.
“If a microbe can hack it up there, above much of the ozone layer, it could survive, albeit briefly, on a trip to the surface of Mars,” said study co-author , David J. Smith, of MARSBOx co-principal investigator and researcher at NASA’s Ames Research Center, in a statement.
Microbes or microorganisms, they have an expansive reach on Earth. It is estimated that there are 1 trillion species on our planet. They can also be found living in harsh environments in extremely variable conditions.
NASA scientists need to know if these microbes could survive on Mars, as they continue to send robotic explorers to the red planet on behalf of humans. That’s why the mission teams behind these rovers, like the newly landed Perseverance rover, take the cleaning of these machines very seriously before launching them to Mars.
To test the likelihood of microbial survival on Mars, the research team placed millions of microbes, including spores of dry, latent fungi and bacteria representing four species of microorganisms, on quartz disks. These disks were placed inside aluminum boxes designed by the studio’s collaborators at the German Aerospace Center.
A mixture of gases similar to those in the Martian atmosphere, dominated by carbon dioxide, was pumped into the boxes. A large scientific balloon carrying the experiment was launched from Fort Sumner, New Mexico, on September 23, 2019.
Blinds were used to protect microbes from the sun during ascent and descent. But once they reached the Earth’s stratosphere 24 miles away, the shutters opened and exposed them to the harsh radiation that was there. Microbes were exposed to this for more than five hours, along with negative average temperatures of 20 degrees Fahrenheit.
In the stratosphere there is a thousand times less pressure than we experience at sea level, as well as very dry air.
When the experiment returned to Earth, 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 provides us with a better understanding of what microbes might persist in environments that were thought to be deadly, such as the surface of Mars, and gives us clues on how to avoid inadvertently taking small hitchhikers to destinations outside the world,” the study said. co-author Ralf Moeller, senior co-researcher at MARSBOx 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 tall brine pools.
Aspergillus niger, a fungus used in the production of antibiotics, was dried to send to the experiment and could also be recovered when it returned from the Earth’s stratosphere.
“A. niger fungus spores are incredibly resistant (to heat, harsh chemicals, and other stressors), but no one had ever studied whether they could survive exposed in space or under intense radiation as we see on Mars,” said co. -The main 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 relive them shows that they are strong enough to withstand wherever humans go, even off the planet.”
It is possible that Aspergillus niger has a pigmentation similar to sunscreen or a cellular structure that is protected.
“This experiment raises many questions about what genetic mechanisms are key to making microbes survive,” Cortesão said. “Do they have ancient evolutionary traits that give them the ability to withstand harsh conditions, or does 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 being planned for MARSBOx in Antarctica, where both the sun’s radiation and the space’s galactic cosmic rays are even more similar to Mars.
“These balloon-flying aerobiology experiments allow us to study microbe resistance in ways impossible in the lab,” Smith said. “MARSBOx provides an opportunity to predict survival outcomes on Mars and help set the boundaries of life as we know it.”
In the meantime, these findings could help plan future missions to Mars. “The renewed focus on robotic and human exploration of Mars amplifies the need for additional analog studies of Mars in the coming years,” the authors wrote in the study.
“With long-term manned 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,” said study author co -Leader Katharina Siems, PhD student in the Aerospace Microbiology Research Group at the German Aerospace Center, in a statement.
“In addition, some microbes could be very valuable for space exploration. They could help us produce supplies of food and materials independently of the Earth, which will be crucial when we are away from home. Microorganisms are closely connected with us, our body, our food, our environment, so it’s impossible to rule them out from space travel. “