Saturn's Gravitational Field, Internal Rotation, and Interior Structure
John D. Anderson1* and
Gerald Schubert2
Saturn's internal rotation period is unknown, though it must
be less than 10 hours, 39 minutes, and 22 seconds, as derived
from magnetic field plus kilometric radiation data. By using
the Cassini spacecraft's gravitational data, along with Pioneer
and Voyager radio occultation and wind data, we obtain a rotation
period of 10 hours, 32 minutes, and 35 ± 13 seconds.
This more rapid spin implies slower equatorial wind speeds on
Saturn than previously assumed, and the winds at higher latitudes
flow both east and west, as on Jupiter. Our related Saturn interior
model has a molecular-to-metallic hydrogen transition about
halfway to the planet's center.
2 Department of Earth and Space Sciences and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90095–1567, USA.
* To whom correspondence should be addressed. E-mail: jdandy{at}earthlink.net
