A Martian experiment in our sky: terrestrial microbes could temporarily survive on Mars, study finds

The two planets may not look very similar, but our stratosphere, a layer of the atmosphere 20 miles above 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, much like the surface of the Red Planet.

Using MARSBOx, or the Microbes in Atmosphere Experiment for Radiation, Survival, and Biological Outcomes, scientists from NASA and the German Aerospace Center collaborated to send four types of microbes into the stratosphere on a balloon.

“If a microbe can hack it up there, above much of the protective ozone layer, it could survive, even briefly, on a trip to the surface of Mars,” said study co-author David J. Smith, MARSBOx co – Principal Investigator and Investigator for NASA’s Ames Research Center, in a statement.

Microbes or microorganisms they have an expansive reach on Earth. There are an estimated 1 billion species of them on our planet. They can also be found living in harsh environments under various extreme 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 cleaning up these machines very seriously before they are launched to Mars.

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To test the probability of microbe survival on Mars, the research team placed millions of microbes, including dry, latent fungal spores and bacteria representing four species of microorganisms, on quartz disks. These discs were placed inside aluminum boxes designed by study collaborators at the German Aerospace Center.

The MARSBOx took off in September 2019. Its door swung open, exposing samples of four different types of microorganisms to the extreme environmental conditions of Earth's stratosphere.

A mixture of gases similar to those of the Martian atmosphere, which is 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.

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Shutters were used to help protect microbes from the sun during ascent and descent. But once they reached the Earth’s stratosphere 24 miles high, the shutters were opened and exposed to the strong radiation there. The 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, in addition to very dry air.

When the experiment returned to the ground, the scientists determined that two of the four species survived the trip, showing that these two could temporarily withstand the harsh conditions of Earth’s stratosphere and potentially the Martian surface.

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“This research gives us a better understanding of which microbes might linger in environments that were once assumed to be lethal, such as the surface of Mars, and gives us clues on how to avoid inadvertently bringing little hitchhikers with us to destinations outside the world.” the study said. co-author Ralf Moeller, MARSBOx co-principal 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-sea brine pools.

Aspergillus niger, a fungus that is used in the production of antibiotics, was dried to send it to the experiment, and it could also be revived once it returned from Earth’s stratosphere.

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“The spores of the fungus A. niger are incredibly resistant to heat, harsh chemicals and other stressors, but no one had studied whether they could survive exposed in space or under intense radiation like the one we see on Mars,” said the co -the main author of the study, Marta Cortesão, a doctoral student of the Aerospace Microbiology Research Group of the German Aerospace Center, in a statement.

“The fact that after their MARSBOx flight we could revive them shows that they are brave enough to endure wherever humans go, even off-planet.”

Aspergillus niger may have a pigmentation similar to a sunscreen or a cellular structure that protects itself.

“This experiment raises many questions about what genetic mechanisms are key to making microbes able to survive,” Cortesão said. “Do they carry ancestral evolutionary traits that give them the ability to withstand harsh conditions, or does adaptation 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 radiation from the sun and galactic cosmic rays from space are even more similar to Mars.

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“These flying balloon aerobiology experiments allow us to study the resilience of the microbe in ways that are impossible in the laboratory,” Smith said. “MARSBOx provides the opportunity to predict survival outcomes on Mars and help establish the limits of life as we know it.”

Meanwhile, these findings could help plan future missions to Mars. “The renewed focus on human and robotic exploration of Mars amplifies the need for further analogous Mars studies in the coming years,” the authors wrote in the study.

“With long-term manned missions to Mars, we need to know how microorganisms associated with humans would survive on the Red Planet, as some may pose a health risk to astronauts,” said study co-lead author Katharina Siems. , a doctoral student in the Aerospace Microbiology Research Group of the German Aerospace Center, in a statement.

Also, some microbes could be invaluable for space exploration. They could help us produce food and material supplies independently of Earth, which will be crucial when you are away from home. Microorganisms are closely related to us; our body, our food, our environment, so it is impossible to rule them out of space travel. “


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