Murray, C.D., Beurle, K., Cooper, N., Evans, M., Williams, G.A. (2007). "Cassini ISS observations of embedded satellites in Saturn's F ring." Royal Astronomical Society National Astronomy Meeting, P25.3.


Abstract
It has been known from Voyager observations that Saturn's narrow F ring exhibits a large degree of time varying radial and azimuthal structure. The mechanism by which the shepherding moon Prometheus produces regular structures is now well understood but images from the Imaging Science Subsystem (ISS) experiment on the Cassini spacecraft show that the F ring exhibits additional features that are not easily explained by the perturbing effect of Prometheus alone. Stellar occultations by the Cassini UVIS experiment (Meinke et al., AAS DPS Meeting 38, 47.02, 2006) have detected 9 events suggestive of objects with diameters in the range 30m to 600m. Combining numerical modelling with a detailed analysis of several thousand Cassini ISS images of the F ring, we have discovered new dynamical phenomena which we believe are indicative of the presence of several hundred objects with typical sizes of < 1km orbiting in the immediate vicinity of the F ring's core. ISS images of the F ring also reveal evidence for several collisions with larger objects having semi-major axes within ~100km of the core. The aftermath of the most recent collision in late 2006 can still be detected several months later.