NASA's Cassini mission was successfully completed in 2017. It came up with some amazing findings. It seems that beneath its icy crust, the Saturn moon Encelada harbors all the essential ingredients for life; namely, water and the elements carbon, nitrogen, oxygen, phosphorus and sulfur, as well as many more molecules. These findings were the cue to search for possible life on the moon.
The example of Japanese deep-sea microbes
An interdisciplinary team from the Universities of Vienna, Linz, Hamburg and Bremen under the lead of Simon Rittmann (Department of Ecogenomics and Systems Biology at the University of Vienna) investigated whether microbial life might be possible under the conditions prevailing on Enceladus. For their research, the team used methanogenic microorganisms from the group of the Archaea, because they metabolize hydrogen and carbon dioxide and can withstand high temperatures and pressure – conditions also suspected on Enceladus. They showed that in particular an archaeal strain from the Japanese deep sea could in principle be able to reproduce under the suspected ice-moon conditions.
Bremen laboratory simulates Enceladus conditions
In addition to the biological experiments carried out by the Universities of Vienna and Linz, astronomical-geological experiments were carried out at the Universities of Hamburg and Bremen. A research group led by Professor Wolfgang Bach from the MARUM Center for Marine Environmental Sciences at the University of Bremen made an important contribution to the study by modeling the reactions between water and rocks. This served to simulate the chemical-physical conditions that presumably prevail under the ice crust on Enceladus. “Based on this modeling, we have shown that hydrogen-consuming microorganisms could actually live in the extremely harsh conditions on Enceladus,” says Bach, explaining the results of the Bremen research. However, another aspect was also evident in the study: The data show that there may be a risk of contaminating such ice moons with terrestrial organisms carried by space probes from Earth.
You can read the article “Biological methane production under putative Enceladus-like conditions” at: https://www.nature.com/articles/s41467-018-02876-y (DOI Number: 10.1038/s41467-018-02876-y)
Press release of the University of Bremen.
If you would like to have more information on this topic, feel free to contact:
Prof. Dr. Wolfgang Bach
MARUM – Center for Marine Environmental Sciences
University of Bremen