A Japanese research team has announced the discovery of traces of the largest impact craters in the solar system on a moon of Jupiter.
The group from Kobe University and National Institute of Technology, Oshima College analyzed images of Ganymede’s surface taken by the Voyager and Galileo space probes of the United States.
It found that furrows, or troughs, on Ganymede, the largest moon of the fifth planet of the solar system, are distributed in a concentric pattern spanning some 7,800 kilometers in radius.
The team, including Kobe University associate professor Naoyuki Hirata, concluded that the tectonic structures are marks of a giant crater caused by a major collision, as similar features exist at 1,900-kilometer-radius Valhalla Crater on Callisto, another moon of Jupiter.
The group also studied the conditions for creating such a giant crater through computer simulations. An asteroid of around 150 kilometers in radius, mainly made of ice, may have crashed into Ganymede over 4 billion years ago, it said.
The finding by the team was published on the online edition of U.S. planetary science journal Icarus.