Azimuthal variability of radial structure of Saturn's rings observed by Cassini radio occultations
Abstract
Eight completed Cassini radio occultation observations of Saturn s rings have yielded high spatial resolution 1 km X-band 3 6 cm-wavelength optical depth profiles at twelve distinct ring longitudes The profiles provide a rich resource of information about radial ring structure and its azimuthal variability Additional acquired Ka- and S-band 0 94 and 13 cm-wavelength profiles yield important complementary information about the particle sizes populating the observed structure Of particular interest here is the observed profile variability with observation longitude azimuth Well-known mechanisms responsible for the variability include resonant interaction with exterior satellites gravitational interactions with ring-embedded satellites and resonant forcing of ring edges and narrow ringlets Streamline distortion caused by such mechanisms is clearly evident in the profiles in the form of a host of density waves some bending waves Pan s wake sharp noncircular edges and narrow eccentric ringlets Although much of the observed structure correlates well with known forcing mechanisms some structure does not This includes width profile variations of several narrow gaps and eccentric ringlets as well as several wave-like features Much of the asymmetry is particularly prominent in features within Rings C the Cassini Division and Ring A A different known mechanism responsible for profile asymmetry is related to the rings microstructure Gravitational wakes developing within self-gravitating Keplerian disks result in spatial correlations
- Publication:
-
36th COSPAR Scientific Assembly
- Pub Date:
- 2006
- Bibcode:
- 2006cosp...36.2806M