According to a new space study conducted by researchers from France and the U.S., Saturn may have played a leading role in the formation of Jupiter’s largest moons.
Io, Europa, Ganymede, and Callisto are Jupiter’s four largest moons. They are also referred to as the Galilean moons, named after Galileo Galilei, who discovered them in 1610. Notably, all the four moons are bigger than Pluto. In fact, Ganymede is even bigger than Mercury, which makes it the largest moon in the solar system.
Previous research work on the formation of Jupiter’s moons suggested that the Galilean moons coalesced from a disk of matter surrounding Jupiter during the last stages of the formation of the giant planet. However, it could not be found from where the building blocks of this disk came and how they surrounded Jupiter.
Prior research also suggested that when Jupiter coalesced from the disk of gas and dust that surrounded the young sun, it opened up a gap in the protoplanetary disk. As per researchers, the gap should have isolated the planet from the rest of the protoplanetary disk. Now the question that arises is how Jupiter was able to collect enough solid materials that formed the Galilean moons.
The new study claims that the Galilean moons may have formed with the help of Saturn. For the purpose of the study, the research team developed computer models of the gap that formed in the protoplanetary disk to understand what exactly might have happened when Jupiter and nearby planets were formed.
The research team found that at the outer edge of the gap, a reservoir of planetesimals likely accumulated over time. They discovered that Saturn’s core may have either formed within this reservoir of planetesimals or migrated through it. The planet’s gravitational pull would have scattered the planetesimals toward Jupiter and the inner solar system, which likely provided enough material to form the Galilean moons.
The study findings have already been submitted to The Astrophysical Journal.