How did Jupiter acquire more large moons than Saturn? This is what a recent study published in Nature Astronomy hopes to address as a team of scientists investigated the reasons behind Jupiter having more large moons than Saturn. This study has the potential to help scientists better understand planetary formation and evolution, including how planets acquire moons.
For the study, the researchers used a series of computer models to simulate how Jupiter acquired four large moons—Io, Europa, Ganymede, and Callisto—while Saturn only acquired one large moon—Titan. Additionally, the first three large moons orbit in what’s known as Laplace resonance, meaning their orbits are synced. For example, for every four orbits of Io, Europa orbits twice and Ganymede orbits once.
In the end, the researchers discovered that Jupiter’s massive magnetic field best explained the acquisition of four large moons. The team notes this is due to the magnetic field carving out empty spaces within the circumplanetary disk of gas and dust that eventually forms planetary bodies. In this case, four large moons. In contrast Saturn’s magnetic field was only large enough to form these empty spaces, resulting in any moons that formed orbiting too close to Saturn and being ripped apart. Finally, the team notes these models could be applied to exoplanets and potentially help determine if they possess exomoons.
"Testing planet formation theory is somewhat difficult because we have only our Solar System for reference, but there are multiple satellite systems close to us whose detailed characteristics we can observe," said Dr. Yuri I. Fujii, who is an Assistant Professor at Kyoto University and lead author of the study.
What new insight into moon formation and evolution will researchers make in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Sources: Nature Astronomy, EurekAlert!
Featured Illustration Credit: Yuri I. Fujii/L-INSIGHT [Kyoto University], Illustrator: Shinichiro Kinoshita
