Surface Deposition of Icy Dust Entrained in Europa’s Plumes

Europa, an icy moon of Jupiter, features complex surface characteristics shaped by tidal forces and interactions with its subsurface ocean, making it a key target for astrobiology research. Outgassing plumes have been reported using Earth-based observations and in situ Galileo mission data, though the nature of plumes on Europa remains largely unknown. This study investigates the dynamics of dust entrained in Europa’s water vapor plumes, which is crucial for understanding surface evolution and subsurface interactions. We employ the Direct Simulation Monte Carlo method to simulate these plumes considering various gas production rates and initial velocities. The Direct Simulation Monte Carlo results provide information for dust trajectory modeling to evaluate the effects of gas drag on particle transport during an idealized plume eruption. We explore how gas production rates, initial gas and dust velocities, and dust size distributions influence plume morphology and deposition patterns. Our findings reveal that gas drag plays a significant role in the behavior of dust, with smaller particles (0.001−0.1 μm) becoming widely dispersed, while larger particles (0.1−10 μm) tend to settle near the source. At the highest gas production rate of 1 × 10²⁹ H₂O s⁻¹ considered in this paper, gas drag becomes the dominant force and reduces the influence of initial ejection velocities. Our study also provides essential insights into surface−subsurface interactions on Europa, aiding in interpreting the upcoming observational data from the missions of JUICE and Europa Clipper, which will further explore these intriguing phenomena.