In order to help with the detailed planning of ESA’s Jupiter Icy Moons Explorer mission, Juice, and in particular the study of Jupiter’s largest moon Ganymede, the spacecraft’s JANUS camera team at the German Aerospace Center DLR has created a new global mosaic of the moon based on data collected by NASA’s Voyager and Galileo missions.

Voyager 1 and 2 flew by Ganymede in the late 1970s, while Galileo imaged the moon in the 1990s as part of its tour of the Jovian system. The mosaic presented in this video comprises 118 Voyager images and 88 Galileo images, resulting in a 1.7 billion pixel map with a spatial resolution up to 359 m/pixel.

Ganymede is the largest moon in the Solar System – even larger than planet Mercury – with a thick crust of ice on top of a global water ocean, and evidence for wide-spread resurfaced regions indicating periods of geological activity. One of the main science goals of Juice is to study Ganymede and its neighbour ocean-bearing moons Callisto and Europa to better understand such water worlds and their habitability potential.

The Juice mission will culminate in orbiting Ganymede, allowing an in-depth study to pry deeper into its secrets. Imaging with JANUS will greatly improve the definition of the moon's surface, mapping it in four colours and pushing the resolution up to an astonishing 7 m/pixel in selected regions of interest.

The mosaic was produced under the leadership of Elke Kersten at the German Aerospace Center DLR. Technical information, as well as the mosaics themselves, can be found at https://janus.dlr.de

Credit: Lightcurve Films / DLR