In a groundbreaking discovery, researchers have found evidence of life 13 feet below the surface of the Atacama Desert, the world’s driest desert. This hidden microbial “biosphere” is one of the deepest found in Atacama soils and could provide valuable insights into the search for life on Mars.
The Atacama Desert, known for its extreme conditions, receives as much sunlight as Venus and is one of the most arid and inhospitable places on Earth. Despite these harsh conditions, some bacteria manage to survive in the desert’s salty, mineral-rich soils. The newly discovered microbial community is completely isolated from the surface and resides in soils between 6.6 and 13 feet deep.
Dominant among these microbes are Actinobacteria, a diverse group of bacteria known for thriving in other extreme environments, such as the Arctic, boiling hot springs, and salty seas. The researchers also discovered bacteria belonging to the phylum Firmicutes, which can survive high salt concentrations and do not require oxygen to thrive.
Bacteria were abundant in the top 2.6 feet of soil, but their numbers dwindled between 2.6 and 6.6 feet deep due to high salt concentrations. However, the researchers discovered a “transition zone” to a stable microbial community at a depth of at least 6.6 feet, which coincided with a change from clay-rich soils known as playa deposits to ancient river deposits.