Close-range remote sensing of Saturn’s rings during Cassini’s ring-grazing orbits and Grand Finale

Tiscareno, M.S. and Nicholson, P.D. and Cuzzi, J.N. and Spilker, L.J. and Murray, C.D. and Hedman, M.M. and Colwell, J.E. and Burns, J.A. and Brooks, S.M. and Clark, R.N. and Cooper, N.J. and Deau, E. and Ferrari, C. and Filacchione, G. and Jerousek, R.G. and Le Mouélic, S. and Morishima, R. and Pilorz, S. and Rodriguez, S. and Showalter, M.R. and Badman, S.V. and Baker, E.J. and Buratti, B.J. and Baines, K.H. and Sotin, C. (2019) Close-range remote sensing of Saturn’s rings during Cassini’s ring-grazing orbits and Grand Finale. Science, 364 (6445). ISSN 0036-8075

Abstract

Saturn’s rings are an accessible exemplar of an astrophysical disk, tracing the Saturn system’s dynamical processes and history. We present close-range remote-sensing observations of the main rings from the Cassini spacecraft. We find detailed sculpting of the rings by embedded masses, and banded texture belts throughout the rings. Saturn-orbiting streams of material impact the F ring. There are fine-scaled correlations among optical depth, spectral properties, and temperature in the B ring, but anticorrelations within strong density waves in the A ring. There is no spectral distinction between plateaux and the rest of the C ring, whereas the region outward of the Keeler gap is spectrally distinct from nearby regions. These results likely indicate that radial stratification of particle physical properties, rather than compositional differences, is responsible for producing these ring structures. © 2019 American Association for the Advancement of Science. All rights reserved.