Mystery Behind Saturn's Moonlets and Rings Finally Revealed

Researchers may have found new information that could cast light on Saturn's moonlets, the small natural satellites located in one of Saturn's rings. The findings could unlock the mysteries surrounding planet formation.

Saturn's F ring, where the moonlets are located, has long been a source of interest and study for scientists. It features rapid change on timescales the range from mere hours to years, and could possibly be the only location in the solar system where collisions occur on a daily basis.

The study, published in the journal Scientific Reports, used a new computer model to examine the high population of moonlets in Saturn's rings. Since powerful tidal forces were thought to minimize the clumping of particles necessary to create these moonlets, their presences in Saturn's F ring was a mystery before now.

Researchers found that the nearby "shepherd" moon, Prometheus, directly influences the formation of moonlets in Saturn's F Ring, the outermost of the dense rings. These moonlets can then create their own structures within the ring.

Although previous numerical modeling had used a massless F ring--particles were non-interacting with each other--interacting with Prometheus, this new modeling that the scientists used assumed an F ring with mass where all particles were gravitationally interacting.

The researchers found an accelerated growth of the density seen at the same places on the streamer-channel edges, structures created when Prometheus moves toward and then back away from the F ring. In fact, they found an increase around five percent each orbital period for the first five orbits in comparison to the zero percent increase for the same areas over the same time period using a non-interacting model.

What does this mean for scientists? The results show new insights into how exactly Saturn's rings form, and may give a small-scale example of how planets form. The interacting forces that the researchers modeled could allow them to model other interactions on other planets, as well.