Beneath the bone-dry surface of Chile’s Atacama Desert, scientists have discovered a functional microbial community that challenges our ideas about what life might be like. While the surface remains one of the harshest environments on Earth, about two meters underground lies a “hidden oasis” protected from high solar irradiance and complete desiccation. This underground community is primarily made up of unique bacteria that harvest water from minerals that is critical for survival. The researchers used cutting-edge DNA sequencing and geochemical techniques to make the discovery. Their work shows that life can thrive without any connection to the ground. This discovery not only changes our view of where life might exist on Earth, but also provides valuable insights into the search for similar life forms on Mars or other barren planets.
Scientists discover secret underground life 2 meters underground in Chile’s Atacama Desert
As noted in the magazine Proceedings of the National Academy of SciencesIn El Yunque Valley, a team of scientists has discovered a variety of microorganisms living two meters below the surface. This area is the driest part of the Atacama Desert. Surface organisms depend on rare rainfall, but these underground microbes don’t depend on the atmosphere at all. The researchers used advanced molecular tools to show that these bacteria are more than just inactive spores. Instead, they form a metabolically active and functioning ecosystem that thrives in constant darkness.
How gypsum pores keep an oasis alive
The presence of porous plaster allows this hidden oasis to survive. This mineral has tiny pores that trap small amounts of water and serve as storage sites for microorganisms. Bacteria of the genus Actinobacteria are extremely tolerant taxa that make up the majority of this community, according to the journal PNAS Nexus. They learned how to harness water bound by minerals, allowing them to live in places that were once considered barren.
Why scientists are searching beneath the surface of Mars
This discovery provides a clear example of how we can explore Mars from Earth. Mars has harsh environmental conditions, with deadly radiation and freezing temperatures, so scientists believe that any life there could exist below the surface, like what we see in the Atacama Oasis. The discovery of habitable space two meters below the most Mars-like region of Earth marks a paradigm shift. Future planetary missions should focus on subsurface sampling to search for signs of life beyond Earth.
Research team uses salt and water chemistry to track ancient life
The team took steps to rule out surface contamination as the cause of their findings. To do this, they used “genomic” and “geochemical” methods. As noted in the journal PNAS Nexus, by examining the salt content and determining the age of the water in the minerals, they concluded that these microorganisms have been present in the soil over geological time scales. Their presence is not affected by current surface climate conditions.
