Locations of Hotspots on Io from Galileo Ssi Eclipse

Introduction: Galileo SSI obtained many images of Io in eclipse by Jupiter, in which the only light that reached the camera was due to hotspot emissions from active volcanoes and from diffuse atmospheric/plume glows [1]. During the first orbits of the Galileo mission, there were full disk eclipse images taken of nearly the entire surface of Io. We correlated these images with high resolution basemaps of Io in order to determine the locations of all hotspots with respect to surface features. This process helps us know which small paterae (volcanic depressions) or lava flows were thermally active at a given time. In addition, it tells us where in a large lava flow field or giant patera (such as the 200 km diameter Loki) the active eruption was occurring during the observations. We use this work to monitor changes over time at various hotspots on Io, as well as global waxing and waning of hotspot activity.