Although the Voyager and Cassini spacecraft later made detailed observations of the F ring and its shepherd satellites, their origin remained mystery till now and the Japanese scientists have revealed the origin breaking the code finally.
In their simulations using the computer systems at the National Astronomical Observatory of Japan, HYODO and OHTSUKI revealed that the F ring and its shepherd satellites formed as these small satellites with a dense core collided and partially disintegrated.
It means the system of the F ring and its shepherd satellites is a natural outcome of the formation process of Saturn’s ring-satellite system and it explains similar rings and shepherd satellites of Uranus, Jupiter and Neptuen which are similar to those of Saturn.
HYODO, now a visiting scholar at the Institut de Physique du Globe de Paris in France, said: “Through this study, we were able to show that the current rings of Saturn reflect the formation and evolution processes of the planet’s satellite system.”
Ohtsuki further said, “As plans are underway in and outside of Japan to explore the satellite system of Jupiter and the satellites of Mars, we will continue to unravel the origin of satellite systems, which is key to understanding the formation process of planetary systems.”
Figure 2: Schematic Illustration of the Latest Satellite Formation Model
Side view of Saturn’s ring-satellite system.
(Top) Saturn’s rings used to be more massive than they are today, and they spread outwards due to collisions and gravitational interactions between particles.
(Bottom) When particles move sufficiently outward, they merge into satellites due to mutual gravity. These satellites then move farther away from Saturn. Consequently, the satellites that formed earlier when the rings were more massive are larger and located farther out, whereas multiple small satellites tend to form just outside of the main rings at the final stage of the satellite system formation.