@article{4dd75c6d157a49b1b5b554ceb472f401,
title = "Measurement and implications of Saturn's gravity field and ring mass",
abstract = "The interior structure of Saturn, the depth of its winds, and the mass and age of its rings constrain its formation and evolution. In the final phase of the Cassini mission, the spacecraft dived between the planet and its innermost ring, at altitudes of 2600 to 3900 kilometers above the cloud tops. During six of these crossings, a radio link with Earth was monitored to determine the gravitational field of the planet and the mass of its rings. We find that Saturn{\textquoteright}s gravity deviates from theoretical expectations and requires differential rotation of the atmosphere extending to a depth of at least 9000 kilometers. The total mass of the rings is (1.54 ± 0.49) × 10 19 kilograms (0.41 ± 0.13 times that of the moon Mimas), indicating that the rings may have formed 10 7 to 10 8 years ago. ",
author = "L. Iess and B. Militzer and Y. Kaspi and P. Nicholson and D. Durante and P. Racioppa and A. Anabtawi and E. Galanti and W. Hubbard and Mariani, {M. J.} and P. Tortora and S. Wahl and M. Zannoni",
note = "We thank J. W. Armstrong, J. Cuzzi, M. Di Benedetto, S. Finocchiaro, J. Fortney, R. French, L. Gomez-Casajus, M. Gregnanin, M. Hedman, R. A. Jacobson, E. Marouf, N. Movshovitz, and L. Spilker for their suggestions and contributions. We are grateful to the Cassini Radio Science operations team members (E. Barbinis, D. Kahan, J. Gao, C. Lee) for supporting the experiments described in this paper. We also thank the DSN and ESA personnel involved in the acquisition of the data. L.I. thanks the late Bruno Bertotti for his mentorship and contributions to the Cassini mission. Funding: Support for this work was provided by the Italian Space Agency (L.I., D.D., P.R., M.J.M., P.T., and M.Z.), NASA{\textquoteright}s CDAP program (B.M., W.H., and S.W.), the Cassini Project (P.N. and A.A.), and the Israeli Space Agency (Y.K. and E.G.). All authors acknowledge support from the Cassini Project. Author contributions: L.I. led the experiment and supervised the data analysis. D.D. and P.R. carried out the gravity data analysis. B.M., W.H., and S.W. contributed interior models and the differential rotation with CMS method. Y.K. and E.G. contributed the models on differential rotation with finite depth flows. P.N. contributed the ring mass interpretation. A.A. coordinated the experiment operations and data acquisition. M.J.M., P.T., and M.Z. helped with the data analysis.",
year = "2019",
month = jun,
day = "14",
doi = "https://doi.org/10.1126/science.aat2965",
language = "الإنجليزيّة",
volume = "364",
journal = "Science",
issn = "0036-8075",
publisher = "American Association for the Advancement of Science",
number = "6445",
}