Soda lakes on Enceladus
Commonly known as soda lakes or oceans, carbonate-rich waters are great at letting phosphorus accumulate. That’s because carbonates are more prone to bond with calcium or other cations, forming carbonate or phyllosilicate minerals and leaving phosphorus available for life.
This geophysical phenomenon is seen on Earth, too, where soda lakes such as the Mono Lake in California have 50,000 times higher phosphorus levels than other waters. That abundant phosphorus supports complex ecosystems, including several species of fish, algae, and fungi.
“[Phosphorus] serves as a critical medium between solid Earth and its biosphere, as it is widely thought to control the level of biological production across a geological timescale,” Jihua Hao, a senior research scientist in China and one of the study’s authors, told Astronomy.
As to where the phosphorus on Enceladus came from, carbonaceous chondrite meteorites are a likely suspect. These remnant rocks date back to the formation of the outer solar system.
Our Sun has “an unusually high amount of [phosphorus] compared with nearby stars,” planetary astrophysicist Natalie Hinkel told Astronomy, “which has been beneficial for life on Earth.” And not surprisingly, stars, planets, moons, and meteoroids from the same stellar cloud often have similar compositions.
“If you look at how much [phosphorus] is in the most primitive carbonaceous chondrites and how much rock we think is inside Enceladus,” Glein told Astronomy, “the conclusion is that Enceladus should easily contain enough phosphorus feedstock to generate a relatively phosphorus-rich ocean.”