Evidence for temporal variability of Enceladus' gas jets: Modeling of Cassini observations
Dougherty, Michele K.; Saur, Joachim; Simon, Sven; Neubauer, Fritz M.; Strobel, Darrell F.; Russell, Christopher T.; Pappalardo, Robert T.; Schilling, Nico
Germany, United States, United Kingdom
Abstract
Time variability of Enceladus' gas plume is deduced from a joint investigation of Cassini spacecraft magnetic field data obtained during the first three flybys E0, E1 and E2 and neutral density measurements during the E2 flyby with a model that describes Enceladus' plasma interaction with individual jets. We infer a total plume content of ~7 × 1032 H2O molecules corresponding to a mass loss rate of ~1600 kg/s for the E0 flyby and ~9 × 1031 H2O molecules corresponding to a mass loss of ~200 kg/s for the E1 and E2 flybys. The magnetic field measurements also support upstream/downstream changes of the plume activity locations. On the first three Enceladus flybys Cassini did not fly through the densest parts of the plumes, which were a factor of 10-100 times higher at the same altitudes.