Rhea is Saturn’s largest icy moon (radius: 1RRh = 764 km). It orbits the planet on an equatorial and circular orbit at a distance of about 8.74Rs from its center (1Rs = 60,268 km). Recent studies showed that Rhea is surrounded by a tenuous exosphere composed of oxygen and carbon dioxide (Teolis et al., 2010). Despite that, the main interaction mode of Rhea with the magnetosphere was shown to be plasma absorption. Magnetic field perturbations in Rhea’s interaction region appear to be guided primarily by the formation of a plasma pressure cavity (wake) downstream of the moon and not from mass or momentum loading from the ionized products of this weak exosphere (Simon et al., 2012; Khurana et al., 2008; Roussos et al., 2008).
Rhea
radius
1RRh
RRh
Rhea
radius
764 km
km
circular orbit
distance
about 8.74Rs
Rs
1Rs
Rs
1Rs
60,268 km
km