“Follow the water” is the theme of much of our quest to find life beyond Earth. From narrowing down the so-called Goldilocks zone to where water can be liquid to the discovery of subsurface ocean worlds, we have pinned our hopes on finding what we recognize as life. Now, scientists led by Jihua Hao have published new models for the composition of the subsurface ocean on Saturn’s moon Enceladus and have determined that a key ingredient – phosphorus – should be readily available. [The paper is published in the Proceedings of the National Academy of Sciences.]
Phosphorus is important for the creation of DNA and RNA, the formation of cell membranes, and even bones and teeth in all manner of animals. Up until recently, much of the data analyzed from the Cassini mission couldn’t prove that phosphorus was contained within that subsurface ocean. So this team of researchers worked up some new thermodynamic models that simulated the water’s geochemistry using that Cassini data. It turned out that phosphate minerals would be “unusually soluble”.
Co-author Christopher Glein notes: The underlying geochemistry has an elegant simplicity that makes the presence of dissolved phosphorus inevitable, reaching levels close to or even higher than those in modern Earth seawater. What this means for astrobiology is that we can be more confident than before that the ocean of Enceladus is habitable.
All we need is a mission to Enceladus.
SwRI press release
“Abundant phosphorus expected for possible life in Enceladus’s ocean,” Jihua Hao et al., 2022 September 19, PNAS