Presentation #316.08 in the session “Circumstellar Disks and The Solar System”.
Understanding property of the ice particles of Saturn’s rings is one of the important problems. Cassini determined that the particles contain 93% ice. Ice in the rings has existed for a long time. It is hardly possible to create such ice in a laboratory on Earth to simulate its properties. Ice is a product of water. Recently was found unusual fact the deuterium to hydrogen isotopic ratio for Saturn’s rings is the same as for the Earth (R. Clark et al, Icarus, 2019). It means water in the Saturn’s rings like water on the Earth. There are two possibilities. We can try to find some types of ice on Earth that can match the environmental parameters in Saturn’s rings. You can also try to understand what properties of ice particles can have from the theory of the origin of Saturn’s rings, if it is consistent with the measurements of the Cassini probe. We know 17 types of ice on Earth. As it turned out, type XI ice has stable parameters at the temperature of the rings. Such ice was discovered in Antarctica, its age estimated as 100 years. It may originate of ordinary ice below -32.8 °F. On the other hand, we found that it is possible to construct a theory of the origin of Saturn’s rings if we assume that the ice in the particles of the protoplanetary cloud has diamagnetism . It also turned out that ice XI has stable parameters at 72K and it is diamagnetic. After emerging of Saturn’s magnetic field, all chaotic orbits of the ice particles due to the force of diamagnetic expulsion gradually shifting to the magnetic equator plane, where the minimum magnetic energy of the particles is observed. Finally all particles are trapped in a three-dimensional magnetic well.  Tchernyi, V.V., Kapranov, S.V. Contribution of magnetism to the Saturn’s rings origin. The Astrophysical Journal, May 6, 2020, Vol. 894, No. 1.