The Atacama Desert in western South America is known as the driest place on Earth — so dry, that it’s been used as a testing area for missions to Mars. Annual rainfall in some Chilean regions of the Atacama averages just 1 mm (0.04 in). Other weather stations have never recorded precipitation.
Microbes grow in salt crystals below the Atacama Desert. Credit: Parro et al./CAB/SINC
Yet, in another testament to the pervasiveness and adaptability of life, a team of Spanish and Chilean researchers have found what they’re calling a microbial oasis two meters beneath the surface.
“We have named it a ‘microbial oasis’ because we found microorganisms developing in a habitat that was rich in halite (rock salt) and other highly hygroscopic compounds (anhydrite and perchlorate) that absorb water” explained Victor Parro, researcher from the Center of Astrobiology (INTA-CSIC, Spain) and coordinator of the study.
The hypersaline substrates that the microbes call home attract moisture in the air, which condenses on the surface of the salt crystals and forms thin films of water only a few microns thick. But because “home” is so far below the surface, the environment provides neither oxygen nor light.
Critical to the discovery is an instrument called SOLID (Signs of Life Detector), which was developed by the research team with the aim of using it for future missions to Mars.
The core of SOLID is a biochip, called LDChip, which includes up to 450 antibodies to identify biological material, such as sugar, DNA and protein. Samples can be taken, incubated and processed automatically and the results can be observed in an image with shiny points that show the presence of certain compounds and microorganisms.
“If there are similar microbes on Mars or remains in similar conditions to the ones we have found in Atacama, we could detect them with instruments like SOLID” Parro highlighted.
