Dust Dynamics and Surface Deposition in Europa's Water Vapor Plumes

Wei-Ling Tseng^1*, Ian-Lin Lai², Wing-Huen Ip², Jong-Shinn Wu⁴, Hsiang-Wen Hsu³

¹Earth Sciences, National Taiwan Normal University, Taipei, Taiwan
²Graduate Institute of Astronomy, National Central University, Taoyuan, Taiwan
³LASP, University of Colorado Boulder, CO, USA
⁴Mechanical Engineering, National Yang Ming Chiao Tung University, Hsinchu, Taiwan

* Presenter:Wei-Ling Tseng, email:wltseng@ntnu.edu.tw

Europa, one of Jupiter's icy moons, is characterized by the complex surface features shaped by tidal forces and geological activity, likely linked to its subsurface ocean. Outgassing plumes have been detected through Earth-based observations and Galileo mission data, though their nature remains largely unknown.
This study focuses on the dynamics of dust particles within Europa's water vapor plumes to understand surface evolution and subsurface interactions. Using the Direct Simulation Monte Carlo (DSMC) method, we simulate the water vapor plumes under varying gas production rates (1 × 10²⁷ H₂O s^-1 - 1 × 10²⁹ H₂O s^-1)and initial gas velocities (0.5 - 0.75 km/s). A hybrid model is also used to explore the effects of gas drag on dust dynamics, examining how gas production rates, initial dust velocities, and particle size distributions affect plume morphology and surface deposition.
Our findings reveal that gas drag is critical in plume dust dynamics. Smaller particles (1–100 nm) experience wider dispersion due to gas drag, while larger particles (100 nm–10 µm) settle closer to the source. At higher gas production rates (1 × 10²⁹ H₂O s^-1), gas drag dominates, reducing the influence of initial dust velocities. These results offer valuable insights into Europa's surface-subsurface interactions and will aid in interpreting data from upcoming missions like JUICE and Europa Clipper.

Keywords: Solar System, Galiean Moons, Outgassing