Ganymede, the solar system’s largest moon, is visualised in the foreground with Jupiter at upper left. Researchers say Ganymede may have been hit by a 150-kilometre-wide asteroid in the distant past, blasting out a giant crater seen today in concentric troughs covering most of the moon’s surface. Image: Tsunehiko Kato, 4D2U Project, NAOJ
Researchers have found what may be remnants of the solar system’s largest impact structure, ancient concentric troughs that extend across almost the entire surface of Jupiter’s moon Ganymede.
Re-analysing images captured by NASA’s Galileo Jupiter orbiter and the Voyager 1 and 2 flyby missions, researchers from Kobe University and Japan’s National Institute of Technology Oshima College have identified concentric rings in patches of dark terrain that appear to be centred around a single point.
The presumed impact structure stretches 7,800 kilometres (4,847 miles) across Ganymede, the largest moon in the solar system. For comparison, Ganymede’s circumference is just 16,530 kilometres (10,271 miles).
Long, concurrent furrows visible in Ganymede’s dark and light terrains may be evidence of the solar system’s largest impact structure. Image: NASA
Using simulations carried out by the “PC Cluster” computer at the National Astronomical Observatory of Japan, the team speculates the troughs could have ...