G. L. Tyler claims (Eos, January 29, 1985, p. 41) that there are 22 ringlets in the Saturnian ring and criticizes me be-cause I have given numbers which are or-ders of magnitude larger. The controversy is largely semantic.
It is theoretically expected that the rings should have a “fine structure” [Alfvén, 1984; Alfvén and Cech, 1984] from which we can derive important processes at the formation of the rings and, in a wider context, gain essential information about the evolutionary history of the solar system. A recent study demonstrates that a detailed analysis of the C ring, as well as of the A and B rings, makes it possible to reconstruct certain events which probably occurred 4–5 billion years ago with an accuracy of 1% [Alfvén et al., 1985]. In some regions, e.g., the Holberg minimum, this fine structure is superimposed on a continuous background so that the opacity does not go down to zero; in others, e.g., the Cassini division, it does. Still, similar cosmogonically relevant information can be extracted from both regions. For example, in both regions there is a double peak, which can very well be called a double ringlet.