JunoCam Observations of Io

During multiple Juno encounters with Io in 2023 and 2024, the spacecraft’s imaging system, JunoCam, acquired approximately a hundred images of Io. These images have a range of scales down to 1 km/pixel, and covered more than half of Io’s surface, including the previously poorly resolved northern and southern polar regions. Some of the highest resolution images were acquired of Io’s nightside, illuminated by Jupiter-shine. Here we provide an overview of the JunoCam Io dataset and discussion of the peculiarities of JunoCam’s “pushframe” imaging. Using JunoCam’shigh resolution coverage of the northern polar region, we have developed an improved geologic map of this previously poorly resolved area, and estimated the heights of sixteen previouslyunidentified or poorly imaged mountains. In the higher resolution images, fourteen new ormodified plume deposits were identified as were at least twenty probable new lava flows. Eight“Prometheus-type” volcanic plumes were identified, five of which were associated with areas showing flow-like surface changes.