The Atacama Desert.
Image: NASA

A new study has documented for the first time how certain microorganisms are able to survive the extreme aridity of Chile’s Atacama Desert—the world’s driest—by going dormant for decades.

To survive years without even a drop of rain, the microbes bide their time in a suspended state. When the rain finally arrives, they reactivate and reproduce. According to Washington State University planetary scientist and lead author Dirk Schulze-Makuch, this is the first time that anyone has been able to identify a persistent form of life living in the soil of the Atacama Desert, one of the harshest environments on Earth.

“We believe these microbial communities can lay dormant for hundreds or even thousands of years in conditions very similar to what you would find on a planet like Mars and then come back to life when it rains,” he said in a statement.

Even science benefits from a little good luck, and when Schulze-Makuch and his team went to the Atacama desert for the first time in 2015, it unexpectedly rained. This gave the scientists a rare first-hand look at “an explosion of biological activity” in the soil, according to the release.

When the researchers revisited the site in 2016 and 2017, they found that the microbial samples that came to life during the rains were gradually reverting to a dormant state as the desert dried up again. The study, published in the Proceedings of the National Academy of Sciences, ultimately identified several indigenous Atacama microbe species adapted to the alien environment.

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“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,” Schulze-Makuch said. “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.”

Dirk Schulze-Makuch and his team researching in the Atacama Desert
Image: Dirk Schulze-Makuch

The Atacama Desert covers a 600-mile strip of land along Chile’s Pacific coast, west of the Andes mountains but east of the Chilean Coast Range. It’s the driest non-polar desert on Earth, according to NASA, and the average rainfall is about 1 mm per year.

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The rocky landscape has been exposed to extreme temperatures and intense ultraviolet radiation for thousands of years. It’s often used to simulate a Martian environment, including with NASA’s Atacama Rover Astrobiology Drilling Studies, a program that tests rovers that may one day look for life on Mars.

The study also shows the importance of preserving even the most uninviting landscapes on Earth. Chile recently established two new national parks in popular and beautiful wilds of Patagonia. Maybe more preserved land in Atacama should be next.