II. Rotation and figure: 10.22hours, with differential rotation
observed between equatorial and polar regions; J2/q2 =
0.11 (difference from Maclaurin spheroid due to effects of compression of bulk composition). The bulk composition must have a denser core as a fraction of total mass compared to Jupiter. Differential rotation of cloud layers is observed.
III. Compostion and interior stucture: similar to Jupiter and sun with
H and and He near solar in relative abundance. Saturn is slightly
depleted in He compared to Jupiter and the Sun. (He/H is 0.6 for Sun and
Jupiter; 0.55 for Saturn).
Important structural divisions are similar to Jupiter, with an outer H layer, metallic H layer with He precipitating, and He enriched core.
IV. Thermal structure: effective surface temperature derived from luminosity suggests an internal heat source consistent with cooling form time of formation.
V. Magnetic field: primarly dipole field and smaller than Jupiter with a substantial tilt of diple axis with respect to pole of rotation. The tilt of the dipole may be explained by a thin, convectively stable, conducting layer above a convecting, conducting metallic H layer.
VI. Other features: Prominant ring system and moons. Rings are quite
thin (order of kilometer or two in thickness) and
are composed of discrete particles. Total mass of rings would make a moon on order of 100 km radius. Some of Saturn's moons act as "shepards" in organzing strands and spacing of rings. Radial concentrations or "spoles" are seen in the rings.
Click here for images of Saturn, its rings, and satellites
Future NASA Cassini mission:
Saturn orbiter and Titan atmosphere
probe. Cassini is a joint NASA/ESA project designed to accomplish an
exploration of the Saturnian system with its Cassini Saturn Orbiter and Huygens Titan Probe. Cassini was
launched aboard a Titan IV/Centaur 1997 Oct 15. Before arriving at Saturn, Cassini will first execute two
gravity assist flybys of Venus, then one of Earth, and then one of Jupiter (a "VVEJGA" trajectory) before
arriving at Saturn on 2004 July 1. Upon arrival, the Cassini spacecraft performs several maneuvers to achieve
an orbit around Saturn. Near the end of this initial orbit, the Huygens Probe separates from the Orbiter and
descends through the atmosphere of Titan. The Orbiter relays the Probe data to Earth for about 3 hours while
the Probe enters and traverses the cloudy atmosphere to the surface. After the completion of the Probe mission,
the Orbiter continues touring the Saturnian system for three and a half years. Titan synchronous orbit
trajectories will allow about 35 flybys of Titan and targeted flybys of Iapetus, Dione and Enceladus. The
objectives of the mission are threefold: conduct detailed studies of Saturn's atmosphere, rings and
magnetosphere; conduct close-up studies of Saturn's satellites, and characterize Titan's atmosphere and