Nov. 9 (UPI) -- To better understand the limits of survival in our solar system and beyond, researchers exposed microbial communities to conditions replicating the harsh environment found on Mars. The microbes were surprisingly resilient.
An improved understanding of life's limits can aid scientists as they search for biomarkers and signs of life throughout the solar system.
Mars is cold, with an average temperature of negative 63 degrees Celsius. Its air pressure is also several hundred times less than Earth's and intense radiation, including gamma rays, regularly bombard Red Planet's surface.
Scientists at Lomonosov Moscow State University replicated these harsh conditions in a small chamber in the lab. The test subjects included microbial communities collected from the Arctic permafrost. Researchers also sampled layers of ancient permafrost that haven't melted for 2 million years.
Astrobiologists estimate the sediment layers on Mars act similarly to ancient Arctic permafrost, preserving microbes in a cryo-conserved state.
"In a nutshell, we have conducted a simulation experiment that covered the conditions of cryo-conservation in Martian regolith," Vladimir S. Cheptsov, a post-graduate student at LMSU, said in a news release.
The tests results showed the permafrost microbes were surprisingly resilient. Prokaryotic cells and metabolically active bacterial cells survived as long as the control communities. Cultured bacteria, microbes growing on nutrient media, didn't fair as well.
Researchers were surprised to find significant biodiversity among the microbes in the permafrost exposed to Mars-like radiation. The microbial communities weren't unaffected, however. Their makeup changed as a result of exposure, with certain strains becoming more dominant.
Researchers published the results of their experiments this week in the journal Extremophiles.
"The results of the study indicate the possibility of prolonged cryo-conservation of viable microorganisms in the Martian regolith," researchers wrote. "The data obtained can also be applied to assess the possibility of detecting viable microorganisms on other objects of the solar system and within small bodies in outer space."