Quirks & Quarks

The secret to finding life on Mars begins in Chile's Atacama Desert

The dormant microbial life in Chile's Atacama desert could help determine if life exists on Mars
The Martian landscape on the left, and the Atacama desert on the right. Microbial life in the Atacama desert could be a model for Martian life (Mars - NASA; Atacama Desert - Alessandro Airo)

The Atacama Desert

The Atacama Desert in Chile is the driest desert on Earth. It receives only a few millimetres of rain every year, and many areas of this desert have been known to go decades without a single drop. The Desert is over 100,000 square kilometres in size and is located between two mountain ranges, the Andes and the Chilean Coast Mountains.  Its hyperaridity is explained by the fact that it is high enough in elevation to prevent the transport of moisture from either the Pacific or Atlantic Ocean.      

Microbial life

It was previously assumed that hyperaridity would result in a decrease or a complete lack of microbial life. But scientists including Dr. Alessandro Airo from the Centre of Astronomy and Astrophysics at the Technical University of Berlin, found evidence of the presence of a metabolically active microbial community in the Atacama Desert. Microbial life can remain dormant for long periods of time, even hundreds of years, but become metabolically active following any increase in moisture.  In 2015, the researchers experienced a surprisingly significant rainfall of 8 millimetres shortly before collecting soil samples for their experiments.  The resulting increase in activity proved that microbial life can indeed exist in such a harsh environment.     

Is there life on Mars?

The understanding of microbial life in the Atacama Desert can serve as a working model for Mars.  On that planet - where the environmental stresses are even more extreme - microbial life could also exist in a dormant state beneath the planet's surface.  Although it does not rain on Mars, the planet does experience some moisture events that could bring microbes to life.