Jovian System Data Analysis Program

Cover Page/Proposal Summary

ROSS-99    NRA 99-OSS-01

Date Due: 5/5/99

The spatial characteristics and the variability of Io's volcanism reflect the planet's interior heating and how magma is transferred from the interior to the surface. Io's thermal output spans a wide temperature range, from small areas with temperatures 1500K to broader areas (~100's km2) of volcanic activity with temperatures ranging from 300 to 700 K, to background thermal emission with temperatures down to around 90K. Io's extraordinarily high rates of volcanism and heat flow make it an ideal laboratory for studying planetary volcanism and for providing a window into the possible processes operating in the ancient Earth, Mars, Venus and, possibly, Mercury. The major objectives of this proposal are: (1) to utilize data from the Galileo Europa Mission to extend the temporal range for maps of Io's heat flow and temporal variability; (2) to analyze the temperature distributions of individual hot spots on Io; and (3) to model the dynamics of Io's plumes. This proposal will analyze principally the thermal data from the Galileo NIMS instrument. The significance of the proposed work to NASA's Office of Space Science (OSS) interests focuses on volcanic processes. Volcanism is a fundamental geological processes in the evolution of solid bodies. Io is the only solid body outside the Earth where large-scale active volcanism has been observed. The objectives of this proposal will contribute to understanding Io's dynamic processes and how they have driven Io's physical and chemical evolution. They will also contribute to understanding the removal of heat from the terrestrial planets early in their history, at a time when their heat flows were comparable to that of Io today.