Mystery Solved Behind Birth of Saturn’s Rings

A team of researchers has presented a new model for the origin of Saturn’s rings based on results of computer simulations. The results of the simulations are also applicable to rings of other giant planets and explain the compositional differences between the rings of Saturn and Uranus. The findings were published on October 6 in the online version of Icarus.

The lead author of the paper is HYODO Ryuki (Kobe University, Graduate School of Science), and co-authors are Professor Sébastien Charnoz (Institut de Physique du Globe/Université Paris Diderot), Professor OHTSUKI Keiji (Kobe University, Graduate School of Science), and Project Associate Professor GENDA Hidenori (Earth-Life Science Institute, Tokyo Institute of Technology).

Please visit "Press Release from Kobe University (Oct 31, 2016): Mystery solved behind birth of Saturn’s rings" for details of this research.

Figure: Schematic illustration of the ring formation process. The dotted lines show the distance at which the giant planets’ gravity is strong enough that tidal disruption occurs. (a) When Kuiper belt objects have close encounters with giant planets, they are destroyed by the giant planets’ tidal forces. (b) As a result of tidal disruption some fragments are captured into orbits around the planet. (c) Repeated collisions between the fragments cause the captured fragments to break down, their orbit becomes gradually more circular, and the current rings are formed (partial alteration of figure from Hyodo, Charnoz, Ohtsuki, Genda 2016, Icarus).

[Research Paper]

Journal: Icarus
Title: Ring formation around giant planets by tidal disruption of a single passing large Kuiper belt object
Authors: Ryuki Hyodo, Sébastien Charnoz, Keiji Ohtsuki, Hidenori Genda
DOI: 10.1016/j.icarus.2016.09.012


GRAPE-DR, one of the GRAPE (GRAvity PipE) series, was used in this research. GRAPE is a special-purpose supercomputer operated by CfCA/NAOJ and enables a high-speed computation of gravitational interactions between particles. The peak performances of GRAPE-DR are 1.6 Tflops in single precision and 0.8 Tflops in double precision. In addition to its high performance, GRAPE-DR has superior ability in power efficiency. In June 2010, a GRAPE-DR system developed by NAOJ and the University of Tokyo got a first prize in the Little Green500 list.

[Related links]

- Department of Planetology, Graduate School of Science / Faculty of Science, Kobe University
- Tokyo Institute of Technology / Earth-Life Science Institute
- Institut de Physique du Globe de Paris
- Université Paris Diderot