Earth’s microbes could temporarily live on Mars, a study says

The surface of Mars is a rough frozen desert, but some microbes from Earth could live there for some time, according to a new study. And the researchers didn’t even have to send microbes to Mars to find out.

The two planets may not look very similar, but our stratosphere – a layer of atmosphere 20 miles above the Earth’s surface – has some effects similar to Mars. Our home planet stratosphere experiences low air pressure and high levels of radiation, and is dry and cold – very similar to the surface of the red planet.

Using the MARSBOx, or Atmosphere Microbes Tests for Radiation, Survival and Biological Products, scientists at NASA and the German Aerospace Center collaborated to insert four types of microbes into the stratosphere on a balloon. .

The study was published Monday in the journal Frontiers in Microbiology.

“If a microbe can build it there, above much of the ozone-proof layer, it may be able to survive – no matter how short – on a trip to the surface of Mars,” said research coauthor David J . Smith, MARSBOx co-principal investigator and researcher at NASA’s Ames Research Center, in a statement.

Microbes, or microorganisms, they have wide access to the Earth. There are an estimated 1 trillion species of them on our planet. They are also found living in harsh environments under a variety of real conditions.

Scientists at NASA need to know if these microbes could 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 moves, like the recently landed Perseverance rover, pay attention to the cleanliness of these devices before launching them to Mars.

Perseverance is still the cleanest. It looks for signs of ancient life on Mars, and microbes from Earth could reveal false positives through this exploration, or they could pollute our planet ‘s neighbor.

To test the likelihood of a microbe living on Mars, the research team put millions of microbes, including dried and dormant fungal spores and bacteria representing four species of microorganisms, on quartz discs. These discs were housed inside aluminum boxes designed by the survey colleagues at the German Aerospace Center.

A mixture of gases similar to those in the Martian atmosphere, which is controlled by carbon dioxide, was pumped into the boxes. A large science balloon carrying the experiment was released from Fort Sumner, New Mexico, on September 23, 2019.

Vessels have been used to help protect the microbes from the sun during ascent and descent. But once they reached the Earth’s stratosphere 24 miles up, the shutters opened and exposed to the harsh radiation there. The microbes were exposed to this for more than five hours, along with an average temperature of 20 degrees Fahrenheit.

In the stratosphere, there is a thousand times less weight than we get at sea level, plus very dry air.

When the experiment returned to the ground, the scientists concluded that two of the four species survived the trip, confirming that both of these things could temporarily withstand the harsh conditions of the Earth’s stratosphere and, possibly, , Martian surface.

“This research gives us a better understanding of what microbes might be living in environments that were once assumed to be lethal, such as the surface of Mars, and gives us insights. on how we can avoid taking tiny hitchhikers to destinations outside the world, “said study coauthor Ralf Moeller, co – principal investigator of MARSBOx and head of Microbiology Research Group Aerospace at the German Aerospace Center, in a statement.

Surviving species included Staphylococcus capitis and Salinisphaera shabanensis. The first is bacteria associated with human skin and the second is bacteria found in deep-sea brine baths.

Aspergillus niger, a fungus used in the manufacture of antibiotics, was dried to test, and was also able to regenerate once it returned from the Earth’s stratosphere.

“Spores from the A. niger fungus are highly resistant – heat, harsh chemicals, and other pressures – but no-one has studied whether they can survive open space or under intense radiation as we can see. Mars, “study co-author Marta Cortesão, a doctoral student at the Aerospace Microbiology Research Group at the German Aerospace Center, said in a statement.

“The fact that, after their MARSBOx flight, we were able to revive them shows that they are brave enough to suffer wherever people go, even off the planet . “

It is possible that Aspergillus niger has sunscreenlike pigmentation or a self-defending cell structure.

“This test raises many questions about what genetic mechanisms are important in causing microbes to survive,” said Cortesão. “Do they carry old evolutionary markers that give their ability to withstand harsh conditions, or does the change to their current environment justify many other environmental challenges? “

Future research could help scientists find out why these microbes came to life. A continuous flight is planned for MARSBOx in Antarctica, where both radiation from the sun and galactic cosmic rays from space are even more like Mars.

“These balloon aerobiology tests allow us to study the stability of the microbe in ways that are impossible in the laboratory,” said Smith. “MARSBOx allows the prediction of results survive on Mars and help establish the boundaries of life as we know it. “

In the meantime, these decisions could help plan future missions to Mars. “The renewed focus on Mars robotic and human exploration increases the need for additional Mars analog studies in the coming years,” the study authors wrote.

“With long-term crew missions to Mars, we need to know how human-related microorganisms would survive on the Red Planet, as some could pose a health risk to astronauts,” he said. co-directed study author Katharina Siems, a doctoral student in the Aerospace Microbiology Research Group of the German Aerospace Center, in a statement.

“In addition, some microbes could be extremely useful for space exploration. They could help us to make food and products independent of the Earth, which will be vital when they are far from home. Microorganisms are closely linked to us: our body, our food, our environment, so it is impossible to control them out of space travel. “