Jupiter’s massive moons prevent Saturn-like icy ring formations

The gigantic moons of Jupiter prevent giant icy ring formations like Saturn, according to new research by the University of California, Riverside (UC Riverside).

"We found that the Galilean moons of Jupiter, one of which is the largest moon in our solar system, would very quickly destroy any large rings that might form," said UCR astrophysicist Stephen Kane, who led the research.

Kane and his graduate student Zhexing Li ran a dynamic computer simulation accounting for the orbits of four main Jovian moons - Io, Europa, Ganymede, and Callisto - as well as the orbit of the planet itself, and information about the time it takes for rings to form.

According to the researchers, if moons are massive enough, their gravity can toss the ice out of a planet's orbit, or change the orbit of the ice enough so that it collides with the moons. As a result, it is unlikely that Jupiter had large rings at any point in its past.

"Massive planets form massive moons, which prevents them from having substantial rings," Kane said.

All four giant planets in our solar system - Saturn, Neptune, Uranus and also Jupiter - do in fact have rings. However, both Neptune and Jupiter's rings are so flimsy they're difficult to view with traditional stargazing instruments, the researchers said.

Rings offer evidence of collisions with moons or comets that may have happened in the past, helping astronomers understand the history of a planet. The rings' shape and size as well as the material's composition offer an indication of the type of event that formed them.

Their results will soon be published in the Planetary Science journal. More details can be found here.