1200 scientists from 52 countries have spent ten years mapping an enormous ecosystem deep in the soil.
In an environment without sunlight, with an extremely high temperature and high pressure, billions of microorganisms thrive. These small organisms, which occur at a depth of more than 2.5 kilometers, have survived for millions of years in isolation.
The new research has revealed that they can cope with much less energy than previously thought possible.
Some are so-called archaea, which are among the oldest and most primitive forms of life.
Organisms live at 120 ° C
Archaea survive in an oxygen-free environment and are often extremophiles, which means that they occur in an environment that is, for example, extremely salty, acidic or hot.
The scientists found organisms that lived deep in the soil at temperatures of more than 120 ° C.
New research shows that 70% of all bacteria and archaea live in the soil. These living things are deeper than previously thought possible.
This is a new record, but the scientists are convinced that there are still unknown organisms hidden in deeper soil layers.
So far, drill samples up to 5,000 meters in depth have been analyzed.
Life thrives in the deepest hole
When they took the samples, the scientists assumed they would find a limit to the maximum depth at which life can occur, but that was not the case.
Life has apparently penetrated further into the soil than we can drill.
According to the researchers, this knowledge about underground life also extends the conditions for life on other planets. We may find life in the future in places that we had previously thought impossible.