This entwining of data and models is key. If a model doesn’t have enough data, it is likely to miss important details. When it comes to understanding worlds, chemistry can play a significant role that is easy to forget. The Cassini mission to Saturn was able to catch samples of material from the geysers on Enceladus and determined that the moon has salty sub-surface seas. Gravitational measurements, and heat calculations, in combination with these salty measurements, build up a picture of ice building up at the equator and melting at the poles, likely creating a gradient in salinity as we see in Earth’s southern seas. 

When saltwater freezes, the salt gets left behind in the unmelted water, making that water heavier, and driving currents. This work is published in Nature Geoscience with first author Ana Lobo who explains: Knowing the distribution of ice allows us to place constraints on circulation patterns. 

Coauthor Andrew Thompson adds: Understanding which regions of the subsurface ocean might be the most hospitable to life as we know it could one day inform efforts to search for signs of life.

Data and models, working together, this is how we figure out the universe.

More Information

Caltech press release

“A pole-to-equator ocean overturning circulation on Enceladus,” Ana H. Lobo et al., 2021 March 25, Nature Geoscience