- 1Aix-Marseille University, Laboratoire d'Astrophysique de Marseille, Marseille, France
- 2Institut Universitaire de France (IUF), France
Modeling the formation conditions of the Galilean moons remains a significant challenge. While it is widely assumed that the moons formed within a circumplanetary disk (CPD) that surrounded Jupiter during the final stages of its growth, the physical properties and composition of this disk remain poorly constrained in theoretical models.
One approach to infer the properties and composition of the CPD is to use the bulk composition of the Galilean moons as a reference to extract compositional trends for the disk. A notable example is the gradient in water content with distance from Jupiter: from completely dry Io to a 1:1 water to rock ratio on Ganymede and Callisto. This gradient strongly suggests that the CPD exhibited a corresponding water abundance gradient during its formation.
With the JUICE and Europa Clipper missions currently cruising to the Jovian system, the coming decade will provide an unprecedented opportunity to study Europa, Ganymede, and Callisto. These missions are expected to refine our understanding of the bulk composition of the moons and provide new constraints for CPD models.
In this context, we aim to model the midplane volatile species composition of the CPD using a 2-dimensional proprietary framework. The model assumes a quasi-stationary disk heated by viscous stress, infalling gas, and the young, hot Jupiter. A key feature of the model is the presence of shadow regions that can be up to 100 K cooler than their surroundings and persist for up to 100 kyr.
Our results indicate that the profile of volatile species in the midplane shows enrichment peaks during the early evolution of the disk. However, maintaining these enrichments requires an accretion rate to the CPD of about 10-7 Mjup/yr for at least 1 Myr. If the accretion rate decreases too rapidly, the ice abundances rapidly decrease.
In addition, we show that shadows within the CPD can significantly influence its volatile composition on short timescales of less than 100 kyr. These shadowed regions may trap ice of volatile species that would otherwise remain in the vapor phase, thereby altering the overall composition of the CPD.
How to cite: Schneeberger, A., Bennacer, Y., and Mousis, O.: Impact of self-shadowing on the Jovian Circumplanetary disk ice composition, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15614, https://doi.org/10.5194/egusphere-egu25-15614, 2025.
