Scientists conducted research on an ocean at a depth of 480 kilometers on Titan, the largest moon of Saturn, to investigate the conditions for the formation of life.

Titan, Saturn’s largest moon, has long captured the interest of scientists with its dense atmosphere, liquid methane lakes on its surface, and sand-like “dunes”. An international research team led by Antonin Affholder from the University of Arizona and Peter Higgins from Harvard University revisited the possibility of life on this mysterious moon. “POTENTIAL FOR HABITABILITY”

Researchers examined the underground ocean of about 480 kilometers on Titan using biological energy modeling. The findings indicate that this ocean could host simple microbial life forms nourished by organic matter. However, it was noted that this type of life could only exist with a very limited amount of biomass. Affholder remarked that the abundance of organic matter on Titan has been previously seen as a significant opportunity for life by stating: “The abundance of organic matter was interpreted as if there were an unlimited food source for life. But not all organic molecules are usable by life, and the interaction between the surface and the underground ocean is very limited.” This situation makes NASA’s planned Dragonfly mission to Titan even more crucial. THE KEY TO LIFE COULD BE FERMENTATION

Researchers suggested that life on Titan could exist through a simple metabolism pathway like fermentation that does not require oxidizers such as oxygen but operates only with organic molecules. Affholder used the phrase “Fermentation could have evolved in the early stages of life on Earth. We wondered if the same kinds of microbes could also exist on Titan.” ENERGY SOURCE FOR TITANIC MICROBES

The team also investigated whether glycine, the simplest amino acid, could serve as an energy source for hypothetical microbes on Titan. However, simulations showed that only a small portion of the abundant organic matter on Titan could be utilized by such microorganisms. To transport glycine to the underground ocean, Titan would need a surface-to-subsurface transit through a thick ice layer. Rare events like meteor impacts are believed to create temporary melting pools that could facilitate this transfer. In the end, the research revealed that glycine sources could only support a few kilograms of microbial biomass in total. This suggests that, on average, fewer microbes than a cell per liter could be found throughout Titan’s entire ocean. Affholder stated: “Our new study shows that these sources would only support a very small microbial population.” These results do not entirely rule out the possibility of life on Titan, but indicate that such life could exist under extremely limited and harsh conditions.