Modeling Europa’s Dust Plume

Friday, 19 December 2014
Ben Southworth1, Juergen Schmidt2, Mihaly Horanyi3 and Sascha Kempf3, (1)University of Colorado at Boulder, Boulder, CO, United States, (2)University of Oulu, Oulu, Finland, (3)University of Colorado at Boulder, Physics, Boulder, CO, United States
The discovery of Europa maintaining a probably periodic water plume located at its 
south polar terrain constitutes a huge scientific opportunity for an upcoming mission to this 
Galilean moon. Measuring the properties of material emerging from interior sources offers 
an unique scientific opportunity to understand the conditions at Europa’s subsurface ocean. 
Remarkably, the water column density of 1020 m-2 for the Europa plume is similar to the 
density of Enceladus’ water plume of (0.9 +- 0.23)1020m-2. This finding strongly suggests 
that Europa's plume, similar to Enceladus, also contains a few mass percent of water 
ice particles which are formed by (i) nucleation within the vapor streaming through fractures 
in Europa's ice crust and (ii) by mantle growth on shock-frozen droplets on the interface of 
the moon’s subsurface ocean. 

We adjusted the Enceladus plume model by Schmidt et al. (2008) to the conditions at 
Europa and derive the size-dependent speed distribution of the emerging ice particles.
We furthermore derived the 3-dimensional structure of the ice particle plume and computed 
the snowfall pattern of the ice particles on Europa’s surface.