Crack Ganymede, the largest moon of Jupiter, may remain after its collision with another large celestial body, reported in the journal Icarus. If the hypothesis of scientists is correct, then the observed traces can be considered to be the largest impact structure known today.
Ganymede is the largest moon in the Solar system and the ninth largest object in it which exceeds the size of even mercury. Its diameter is 5.2 thousand kilometers, and mass — greater the mass of the moon is approximately two times. Studies of Ganymede through various space stations, including “Voyager-1 and Voyager-2” and “Galileo” showed that its surface is covered with concentric grooves, the width of each of which is a few kilometers. Astronomers assumed that cracks could appear in the result of collision of the moon with another celestial body, but the strength and scale of the event still remain unclear.
Naoyuki Hirata (Naoyuki Hirata) from Kobe University, together with colleagues re-analyzed the images obtained by past missions, and found that cracks on the Ganymede more than previously thought. According to their estimates, the length of the furrows is about 16 thousand kilometers — that is, they are almost completely wrapped around the surface of the Jupiter moon. Simulation built by the astronomers showed that cracks could appear in the result of collision Ganymede with another celestial body with a diameter of 300 kilometers. If so, the traces on Jupiter’s moon is the largest impact structure in the Solar system, which surpasses in size even the pool South pole — Aitken 2500 kilometers: according to scientists, it emerged after the fall of the 200-kilometre asteriod.
The authors suggest that an unknown celestial body fell on Ganymede, about four billion years ago in the area known as the area Marius. Since the moon’s surface has changed due to volcanism and tectonic activity that erased some traces from the surface. However, the striations are preserved on older and dark areas, which cover about a third of the surface, so astronomers see the rest as a result of collision of cracks, but not the impact crater.
The fall of an asteroid would greatly affect the Geology and internal evolution of Ganymede. Therefore, the data obtained in the course of future missions such as JUICE or the Europa Clipper, to verify the authors ‘ conclusions.
Previously, scientists found that Ganymede, along with another moon, IO, leaves fingerprints on the polar lights, which is observed at the poles of Jupiter.