Jupiter’s moon Ganymede is the site of the largest impact crater in the solar system, according to new research from Japan’s Kobe University and the National Institute of Technology, Oshima College.
The team re-examined images from previous probe missions which had passed by Jupiter and its moons and used computer modeling to learn more about this unusual body. It is the largest moon of Jupiter and one of the ten largest bodies in our solar system, and it also has its own magnetic field which is distinct from Jupiter’s magnetic field. Beneath a rocky surface, the moon may be hiding a salty ocean which could even perhaps host life.
In their research, the team identified troughs that lie in concentric rings across the surface of Ganymede. They believe that these are evidence of an enormous impact crater, the result of a collision between the moon and an asteroid with a radius of approximately 93 miles. If this is correct, with a radius of 4,850 miles this would be the largest impact crater in our solar system, overtaking the 1,180-mile radius crater on another of Jupiter’s moons, Calisto. It also means that the impact crater covers a significant amount of the moon’s surface, as it is only a little under 10,300 miles in circumference.
These findings suggest there could be many surprises in store for an upcoming mission to Jupiter’s moons, the European Space Agency’s Jupiter Icy Moons Explorer mission which is set to launch in 2022.
As lead researcher Naoyuki Hirata said in a statement, “The European Space Agency’s JUICE (Jupiter Icy Moons Explorer) mission, scheduled to launch in 2022 and arrive in 2029, will examine Jupiter and its moons, including Ganymede, with instruments such as the GAnymede Laser Altimeter (GALA), which NAOJ is helping to develop, and imaging spectrographs. GALA is being developed mainly by the German Aerospace Center in collaboration with institutes in Switzerland, Spain, and Japan, including JAXA, Chiba Institute of Technology, Osaka University, and NAOJ.
“We hope that JUICE will confirm the results of this study and further advance our understanding of the formation and evolution of Jupiter’s moons.”