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 features in common with Mars. Our home planet’s stratosphere experiences low air pressure and high levels of radiation, and it is dry and cold – just like the surface of the red planet.
Using the MARSBOx, or the microbes in atmosphere for radiation, survival and biological outcome experiment, scientists at NASA and the German Aviation Center collaborated to send four types of microbes onto a balloon in the stratosphere.
“If a microbe can knock it over a large part of the protective ozone layer, it can only survive – however short – on a journey to the surface of Mars,” said co-author David J. Smith , MARSBOx, said. co-principal investigator and researcher at NASA’s Ames Research Center, in a statement.
Microbes, or microorganisms, has an extensive range on earth. It is estimated that there are 1 billion species on our planet. They can also be found in difficult environments under different conditions.
NASA scientists need to know if these microbes can survive on Mars, as they are still sending robotic scouts to the red planet on behalf of humans. Therefore, the mission teams behind these rovers, just like the recently landed Perseverance Rover, take the neatness 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 dried and dormant fungal and bacterial spores representing four species of microorganisms, on quartz disks. These discs were placed in aluminum boxes designed by the study’s collaborators at the German Aviation Center.
A mixture of gases similar to those in the Martian atmosphere, which is dominated by carbon dioxide, was pumped into the boxes. A large science balloon with the experiment was released on September 23, 2019 from Fort Sumner, New Mexico.
Shutters were used to protect the microbes from the sun during ascent and descent. But as soon as they reached the earth’s stratosphere 24 kilometers away, the shutters opened and exposed them to the hard radiation there. The microbes were exposed to this for more than five hours, along with an average temperature of about 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, the scientists determined that two of the four species survived the journey, proving that these two could temporarily withstand the harsh conditions of Earth’s stratosphere and possibly the Martian surface.
“This research gives us a better understanding of what microbes can occur in environments that were previously considered lethal, such as the surface of Mars, and gives us clues on how to avoid accidentally bringing small lifters to the outside world, “said the study. co-author Ralf Moeller, co-principal investigator of MARSBOx and head of the Aerospace Microbiology Research Group at the German Aerospace Center, in a statement.
The surviving species included Staphylococcus capitis and Salinisphaera shabanensis. The first is a bacterium associated with human skin, and the second a bacterium found in deep-sea brine pools.
Aspergillus niger, a fungus used in the manufacture of antibiotics, was dried to send it to the experiment, and it could also revive once it returned from the Earth’s stratosphere.
“Traces of 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. co said. Leading study author Marta Cortesão, a doctoral student at the Aerospace Microbiology Research Group at the German Space Center, in a statement.
“The fact that we were able to revive them after their MARSBOx flight shows that they are heartfelt enough to tolerate wherever people go, even outside the planet.”
Aspergillus niger may have a sunscreen-like pigmentation or a cellular structure that protects itself.
“This experiment raises many questions about what genetic mechanisms are the key to enabling microbes to survive,” Cortesão said. “Do they have ancient evolutionary characteristics that give them the ability to withstand difficult 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 the solar radiation and galactic cosmic rays from space are even more similar to Mars.
“These balloon flight aerobiology experiments allow us to study the microbial resilience of the microbes in ways that are impossible in the laboratory,” Smith said. “MARSBOx provides an opportunity to predict survival results on Mars and determine the life boundaries as we know them.”
Meanwhile, these findings could help plan future missions to Mars. “The renewed focus on Mars robotics and human reconnaissance increases the need for additional Mars analog studies in the coming years,” the authors wrote in the study.
“With long-term missions to Mars, we need to know how micro-organisms associated with humans will survive on the Red Planet, as some may pose a health risk to astronauts,” said Katharina Siems, co-lead study author, a doctoral student in the German Aerospace Center’s Aerospace Microbiology Research Group, in a statement
“In addition, some microbes can be invaluable for space exploration. It can help us produce food and material supplies independently of the Earth, which will be crucial if we are far from home. Microorganisms is closely connected to us; our body, our food, our environment, so it is impossible to eliminate them from space travel. ‘