Cross-eye stereographic view of 11-km-high Tohil Mons and Radegast Patera (dark lava lake) on Io. The resolution of these Galileo Solid-State Imaging Experiment (SSI) images is approximately 150 m/pixel and color data was taken from lower resolution images from orbit C21 observations. To get a sense of scale, Radegast Patera has almost same diameter as Endeavour Crater on Mars, where the rover Opportunity is exploring.

NASA / JPL / Daniel Macháček