Infrared observations of Io from Juno

Abstract

The Jovian InfraRed Auroral Mapper (JIRAM) on board the NASA Juno spacecraft is a dual-band imager and spectrometer, primarily designed to study the Jovian atmosphere and aurorae. In addition to its primary goal, JIRAM has been used to obtain images and spectra of the Galilean satellites, Jupiter's largest moons, when the spacecraft attitude was favourable to achieve this goal. Here we present JIRAM's first images and spectra of Io. These observations are used to characterize the location and possible morphology, and some temperatures, of Io's volcanic thermal sources; the identification of SO2 and the possible identification of other materials. A new hot spot/volcano is identified close to the South Pole of Io, and others are seen in lower latitude regions, which were previously unmapped. Images of the same region taken 2 months apart also show variations of hot spot intensity, possibly due to new lava flows or to lava flow breakouts.