A team of researchers has identified a metabolically active microbial ecosystem situated two meters below the surface of Chile’s Atacama Desert. According to a study published in the journal PNAS Nexus, the community thrives in the Yungay Valley, the driest region of the desert, without any connection to surface moisture or atmospheric conditions.

The study reveals that the microorganisms, primarily extremotolerant Actinobacteriota, survive by extracting water trapped within the microscopic pores of vesicular gypsum. Advanced DNA sequencing and geochemical techniques confirmed that these bacteria are not dormant spores but part of a functioning ecosystem that remains isolated from high solar irradiance and extreme surface aridity.

To validate the findings, the research team utilized salt and water chemistry to rule out surface contamination. Analysis of mineral-bound water indicates that these microbes have inhabited the subsurface for geological timescales, persisting independently of the current hyper-arid climate at the surface.

The discovery is being cited as a significant shift in astrobiological models, suggesting that life on barren planets like Mars may exist in similar subsurface niches protected from surface radiation. Future planetary missions are expected to integrate deeper subsurface sampling protocols to search for signs of extraterrestrial life.