This infrared image of the southern hemisphere of Jupiter's moon Io was derived from data collected by the Jovian Infrared Auroral Mapper (JIRAM) instrument aboard NASA's Juno spacecraft on Dec. 16, 2017, when the spacecraft was about 290,000 miles (470,000 kilometers) from the Jovian moon. In this infrared image, the brighter the color the higher the temperature recorded by JIRAM.
An animation is available at https://photojournal.jpl.nasa.gov/catalog/PIA22599