by Brooks HaysWashington (UPI) Feb 27, 2018
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For the first time, scientists have documented life rebounding in the sandy soil of the world's driest desert, the Atacama Desert. The research has offered new insights into the resiliency of life, as well as a glimpse of what life might look like on Mars.
South America's Atacama Desert is the most Martian-like ecosystem found on Earth. During their survey of the hyperarid environment, researchers from Washington State University found specialized bacteria capable of lying dormant during decades-long droughts. Only when rain finally arrives do the bacteria spring back to life and begin reproducing.
"It has always fascinated me to go to the places where people don't think anything could possibly survive and discover that life has somehow found a way to make it work," planetary scientist Dirk Schulze-Makuch said in a news release. "Jurassic Park references aside, our research tell us that if life can persist in Earth's driest environment there is a good chance it could be hanging in there on Mars in a similar fashion."
The discovery of Schulze-Makuch and his colleagues was quite lucky. Obviously, rain is hard to come by in the Atacama Desert. But when WSU researchers first visited in 2015, rain fell.
Researchers immediately turned their attention to the soil and the biological activity happening there. Genomic analyses of the newly moistened soil samples revealed the presence of native bacterial communities, uniquely adapted to the extreme conditions.
In follow up trips in 2016 and 2017, researchers found the same microbial communities had slowed their reproductive rates and were returning to their dormant state. They detailed their surveys in the journal PNAS.
Martian soil is even colder and drier than the soil of Atacama. But several studies have suggested Mars was once milder and wetter. It's possible microbes on Mars also evolved to survive extreme conditions.
"We know there is water frozen in the Martian soil and recent research strongly suggests nightly snowfalls and other increased moisture events near the surface," Schulze-Makuch said. "If life ever evolved on Mars, our research suggests it could have found a subsurface niche beneath today's severely hyper-arid surface."
This year, Schulze-Makuch and his research partners are once more returning to Atacama to study how the desert's microbial communities survive for so long without water.
"There are only a few places left on Earth to go looking for new lifeforms that survive in the kind of environments you would find on Mars," Schulze-Makuch said. "Our goal is to understand how they are able to do it so we will know what to look for on the Martian surface."
