Models of dust around Europa and Ganymede

TL;DR

This study develops numerical models, supported by laboratory data, to predict dust densities around Europa and Ganymede caused by micrometeoroid impacts, validated with Galileo spacecraft data, aiding future mission planning.

Contribution

The paper introduces a comprehensive numerical model for dust ejecta around Europa and Ganymede, incorporating multiple dust sources and validated against spacecraft data.

Findings

Validated models against Galileo data

Quantified dust densities at various altitudes

Assessed impact of parameter uncertainties

Abstract

We use numerical models, supported by our laboratory data, to predict the dust densities of ejecta outflux at any altitude within the Hill spheres of Europa and Ganymede. The ejecta are created by micrometeoroid bombardment and five different dust populations are investigated as sources of dust around the moons. The impacting dust flux (influx) causes the ejection of a certain amount of surface material (outflux). The outflux populates the space around the moons, where a part of the ejecta escapes and the rest falls back to the surface. These models were validated against existing Galileo DDS (Dust Detector System) data collected during Europa and Ganymede flybys. Uncertainties of the input parameters and their effects on the model outcome are also included. The results of this model are important for future missions to Europa and Ganymede, such as JUICE (JUpiter ICy moon Explorer), recently selected as ESA's next large space mission to be launched in 2022.