NASA scientists sent microbes to Earth’s stratosphere to test their endurance and discovered they can survive the harsh conditions on Mars.
(CN) — A new NASA study released Monday finds that some Earth microbes could temporarily survive on Mars.
Researchers tested the microorganisms’ endurance to Martian conditions by launching them into the Earth’s stratosphere, which resembles conditions on the red planet, according to the study published in the journal Frontiers in Microbiology.
Scientists hope the research, conducted in conjunction with the German Aerospace Center, increases understanding about opportunities for resource independence from Earth.
“We successfully tested a new way of exposing bacteria and fungi to Mars-like conditions by using a scientific balloon to fly our experimental equipment up to Earth’s stratosphere,” said Marta Filipa Cortesão, joint first author of the study from the German Aerospace Center, in a statement. “Some microbes, in particular spores from the black mold fungus, were able to survive the trip, even when exposed to very high UV radiation.”
Understanding microbial endurance during space travel is vital for the success of future missions because extraterrestrial discoveries must be free of Earth-based microbes to avoid contaminating the results.
“With crewed long-term 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 joint author Katharina Siems, also from the German Aerospace Center. “In addition, some microbes… could help us produce food and material supplies independently from Earth, which will be crucial when far away from home.”
Replicating the environment on Mars on Earth is difficult, but above the ozone layer in Earth’s stratosphere, the conditions are remarkably similar.
To conduct their research, scientists launched the microbes into the stratosphere inside the MARSBOx (Microbes in Atmosphere for Radiation, Survival and Biological Outcomes experiment) payload, which was kept at Martian pressure and filled with an artificial Mars-like atmosphere throughout the mission.
The MARSBOx experiment was flown on a NASA scientific balloon mission launched from Fort Sumner, New Mexico, in September 2019. The mission lasted 6.5 hours and reached a sustained altitude of 110,000 feet.
In addition to measuring the ionizing radiation conditions in the stratosphere using onboard instruments, MARSBOx carried nine different types of microorganisms, including bacteria and fungi, in a dormant state to protect them.
“The box carried two sample layers, with the bottom layer shielded from radiation,” Cortesão said. “This allowed us to separate the effects of radiation from the other tested conditions: desiccation, atmosphere, and temperature fluctuation during the flight.”
Top layer samples were exposed to more than a thousand times more UV radiation than levels that cause sunburn to human skin.
While not all the microbes survived the trip, one previously detected on the International Space Station — the black mold Aspergillus niger — was revived after it returned home.
“Microorganisms are closely-connected to us; our body, our food, our environment, so it is impossible to rule them out of space travel,” Siems said.