JOVIAN SYSTEM DATA ANALYSIS PROGRAM PROPOSAL SUMMARY

The scientific objective of this proposal is to describe the active volcanism on Io in space and time. The work proposed here is to analyze the SSI images in much greater detail than in previous studies of the active volcanism (1-3), to reanalyze some of the Voyager data in light of new results, and to collaborate on coanalyses with NIMS, HST, and ground-based observations. Specific tasks include (1) Improved scattered-light corrections of SSI images; (2) Mapping of surface changes (Voyager-Galileo, HST-Galileo, and Galileo-Galileo); (3) Precise location and movement over time of active volcanic vents (hot spots seen in eclipse, and plumes); (4) Estimation of plume particle sizes and eruption rates; and (5) Syntheses of observations to describe and model the volcanology of major active centers on Io. The data analysis proposed here will provide constraints on models for geophysical processes within and around Io. We will provide key information needed for understanding Io's volcanism and effects on the larger Jovian system. Final products will include (1) improved scattered light correction procedures for SSI images; (2) several scientific papers describing new insights into surface changes, plume properties, and the volcanology of the most active centers on Io; (3) improved information for target selection during the Io flybys in late 1999; and (4) new beautiful images of Io for E/PO. (1) McEwen, A., D. Simonelli, D. Senske, K. Klassen, L. Keszthelyi, T. Johnson, P. Geissler, M. Carr, and M. Belton 1997. High-temperature hot spots on Io as seen by the Galileo Solid-State Imaging (SSI) experiment. Geophys. Res. Lett. 24, 2443-2446. (2) McEwen, A.S., and 13 others 1998a. Active volcanism on Io as seen by Galileo SSI. Icarus, in press. (3) McEwen, A.S., and 14 others 1998b. High-temperature silicate volcanism on Jupiter's moon Io. Science, in press.