The largest impact crater in the Solar System may well have been discovered on Ganymede, a moon of Jupiter. On a surface of no less than 7,800 kilometers of radius. It was allegedly caused by an asteroid 150 kilometers in radius hitting the planet at a speed of 20 kilometers per second.

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Ganymede is the largest natural satellite in our Solar system. It is even bigger than Mercury. And when Voyager probes in the late 1970s, then Galileo – between 1995 and 2003 – flew over this Moon of Jupiter, they discovered furrows in him. Years later, researchers from Kobe University (Japan) looked again at these data. After a precise analysis of the orientation and distribution of these furrows, they suggest that they could be the last traces of a giant crater.

If the researchers were initially interested in these grooves, it is because they are supposed to be the oldest characteristics of Ganymede surface. A way to retrace its ancient history, then.

What to explain the internal structure of Ganymede

These furrows would be placed, on the surface of Ganymede, along a ring pattern with a radius of no less than 7,800 km. And the computer simulations allow researchers to suggest that the underlying crater may have been formed by the impact of a asteroid with a radius of 150 km striking at 20 km / s. It would then be, neither more nor less, that the largest impact crater never detected in the Solar system. Much larger than the similar structure already identified on Callisto, another satellite of Jupiter: the crater Valhalla and its 1,900 km radius.

This discovery could explain the origin of the structure of Ganymede in differentiated layers. Such a structure, in fact, requires an enormous contribution of heat. Whose source could well be this asteroid impact. And researchers now hope that future exploration missions can provide them with more precise information on this subject.

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