Evans, M., Porco, C., and Hamilton, D. (2002). "The Orbits of Metis and Adrastea: The Origin and Significance of their Inclinations." American Astronomical Society, DPS meeting #34, #24.03.


Abstract
The Cassini ISS narrow angle camera (NAC) took several hundred images of the main jovian ring in December 2000 and January 2001 during that spacecraft's flyby of the planet Jupiter. The small inner satellites Metis and Adrastea are visible in a subset of these images. In addition there are a small number of Galileo images of these satellites taken during the period 1997 to 2001. If Metis and Adrastea are the source of the material in the jovian main ring, then according to dynamical models (Grun et al. 1980, Icarus 44, 326, Showalter et al. 1987, Icarus 94, 458) the ring's vertical structure will be determined by the inclinations of the rings' source bodies. A definitive measure of the satellites' inclinations would allow a more confident assertion of the relationship between ring and moons. We have fit the orbits of Metis and Adrastea using Cassini data and additional images from the Galileo SSI experiment and have found statistically significant inclinations that can be directly compared to the best estimates for the ring's vertical thickness. In addition, we are investigating past resonant configurations with Io as a possible cause for Metis and Adrastea's small inclinations. We will present the results of all these investigations.