Massive Ancient Asteroid Impact May Have Tilted Jupiter's Moon Ganymede
A new study suggests that Jupiter’s largest moon, Ganymede, may have tilted on its axis after being struck by a massive asteroid around 4 billion years ago. This impact, estimated to be caused by an asteroid 20 times larger than the one that wiped out the dinosaurs on Earth, could have significantly shaped Ganymede's surface and history.
Ganymede is the largest moon in the solar system, surpassing even Mercury and Pluto in size. Beneath its thick, icy crust, previous research has indicated the presence of a salty ocean, which is believed to be 10 times deeper than Earth's oceans. However, many mysteries about Ganymede remain, requiring more high-resolution imagery to better understand its evolution.
The moon’s surface is marked by deep furrows that form a pattern of concentric circles around a specific area. These furrows have led scientists to believe that Ganymede experienced a major impact event. “The Jupiter moons Io, Europa, Ganymede, and Callisto all have unique characteristics, but what caught my attention were these furrows on Ganymede,” said Naoyuki Hirata, an assistant professor of planetology at Kobe University in Japan. “We know these features were created by an asteroid impact about 4 billion years ago, but the size of the impact and its effects were unclear.”
Hirata’s new study, published in the journal Scientific Reports, delves into the origins of Ganymede’s furrowed surface and the aftermath of the ancient collision. These mysteries could be further explored by the European Space Agency’s JUICE spacecraft, which is currently on its way to study Jupiter and its moons.