A recent study suggests that a colossal collision billions of years ago may have significantly reoriented Ganymede, the largest moon of Jupiter.
Researchers from Kobe University analyzed Ganymede’s extensive furrow system, which consists of concentric troughs believed to be remnants of the largest impact structure in the outer solar system.
The center of this furrow system aligns closely with Ganymede’s tidal axis—the imaginary line extending from the moon to Jupiter. This alignment leads scientists to propose that the impact responsible for the furrows caused a substantial redistribution of mass that altered the moon’s orientation.
Simulations indicate that the impactor likely had a diameter of approximately 150 kilometers, much larger than the asteroid that led to the extinction of the dinosaurs, estimated to be around 10 kilometers.
Experts warn that if an asteroid of this size were to strike Earth, it would result in catastrophic consequences, described as a “global sterilizing event.”
Upon impact, the massive asteroid would penetrate Ganymede’s icy crust, reaching the liquid oceans beneath, creating a transient crater and ejecting vast amounts of debris across the moon’s surface.
As this material settled, it formed a dense layer around the impact site, increasing gravitational pull in that region. Over time, this alteration would cause Ganymede to reorient, aligning the impact area with its tidal axis, as indicated by the simulations.
The research team also drew comparisons with a similar event on Pluto, where a significant impact created a basin, resulting in the dwarf planet’s reorientation.
Despite these findings, estimating the size of the colliding object remains complex due to limited data on Ganymede’s gravity and topography.
While the modeling presented in this study sheds light on the potential reorientation process, further research is needed to fully understand the intricacies of Ganymede’s unique icy structure.
