A giant impact may have caused cracks all over Jupiter’s moon Ganymede

By Jonathan O’Callaghan

Cracks in Marius Regio on Ganymede

NASA/JPL/OWW

Jupiter’s moon Ganymede is covered in cracks that may be evidence of a huge collision, making them the largest known impact structure in the solar system.

Ganymede is the biggest moon in the solar system, and the ninth biggest object – larger even than the planet Mercury – measuring more than 5000 kilometres across. It has been visited by multiple spacecraft, including NASA’s Voyager 1 and Voyager 2 probes in 1979, and the Galileo spacecraft from 1996 to 2000.

Images from these spacecraft revealed cracks or furrows on the surface of the moon, …