1,2,- 1University of Bern, Physics Institute, Space Research and Planetary Sciences (WP), Bern, Switzerland (leander.schlarmann@unibe.ch)
- 2Umeå University, Department of Physics, Umeå, Sweden.
Jupiter's Galilean satellites, Io, Europa, Ganymede, and Callisto, are similar in size and mass. Io, the innermost Galilean moon, is subject to extreme tidal forces, making it the most volcanically active body in the Solar System. This causes Io's tenuous atmosphere to be dominated by SO2. On the contrary, the main atmospheric species of the icy Galilean moons are expected to be water-related products, such as H2O, O2, and H2. Furthermore, non-water-related species, such as CO2, have been detected. In this study, we use the Direct Simulation Monte Carlo (DSMC) model ultraSPARTS (ultrafast Statistical PARTicle Simulation package) [1, 2] to compare the atmospheres of the Galilean satellites. For this purpose, we investigate the influence and interaction of various processes, including the sublimation of surface materials, the interaction with the Jovian magnetic field through sputtering and radiolysis, and the outgassing from (cryo-)volcanic plumes. To model the sublimation of SO2 and H2O, we apply a thermal model (THERMPROJRS [3]) to constrain the surface temperature on the satellites. The DSMC method enables us to model the transition from regions dominated by intermolecular collisions to free molecular flow. The atmospheres of the Galilean moons will be studied extensively in the 2030s by the Juice and Europa Clipper missions using high-resolution mass spectrometry, providing an unprecedented opportunity to compare and verify our results with in-situ data.
Acknowledgements:
This work has been carried out within the framework of the National Centre of Competence in Research PlanetS supported by the Swiss National Science Foundation under grant 51NF40_205606. The authors acknowledge the use of ultraSPARTS from Plasma T.I., Taiwan.
References:
[1] http://www.plasmati.com.tw/
[2] Klaiber, L. M. (2024). Three-dimensional DSMC modelling of the dynamics of Io’s atmosphere. PhD thesis, University of Bern.
[3] Spencer, J. R. (1989). Icarus 78, 337-354.
How to cite: Schlarmann, L., Vorburger, A., Mosimann, T., Fatemi, S., Thomas, N., and Wurz, P.: Comparative study of the Galilean moon atmospheres using the DSMC method, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-12684, https://doi.org/10.5194/egusphere-egu26-12684, 2026.
