Me too, that is just incredible.
We are seeing most of the Jupiter facing hemispheres of both Io & Ganymede (obvious really as if they were the anti Jupiter sides, Ganymede would be eclipsing Io, as Ganymede orbits Jupiter at a vastly greater distance than Io). Jupiter is not far off the frame to the right & very slightly in the foreground. Ganymede was 4.035 AU, Io was 4.028 AU & Jupiter 4.022 AU away at the time.
Io clearly displays the darker regions at both polar regions, where the Sulphur is colder than normal away from active volcanic regions & is darker, & on Ganymede both Galileo Regio & Marius Regio are visible, not to mention the shadow of volcanic Io sweeping across the face of the solar system's largest moon Ganymede. Also the bright ejecta from the crater Tros on Ganymede can be made out.
Thank you very much mwbiggs for bringing this here.
Amazing.
Andrew Brown.