Page 45 - Curriculum Visions Dynamic Book

The rings
When people think of Saturn, they immediately think of its spectacular rings.
The rings are just over 270,000 km across but only between 100 m and 1 km thick. In total, this filmy feature contains less matter than the single moon of Mimas.
Each ring is made from myriad tiny ice and rock particles, and the rings are separated by gaps.
The rings mainly lie within a distance approximately equal to Saturn’s diametre. At this closeness to the planet the immense gravity of Saturn prevents the tiny rock fragments from grouping to make new moons. At the same time, if any large moon entered into this zone, it would
be torn apart by Saturn’s gravity and made into more fragments for the rings. This may explain the rings—they are made of the debris, both rock and ice, created when larger moons were torn apart.
The rings were divided by observers on Earth into A, B, and (fainter) C rings, but the Voyager spacecraft missions showed that there were more rings.
gravity The force of attraction between bodies.
matter Anything that exists in physical form.
radius (pl. radii) The distance from the centre to the outside of a circle or sphere.
voyager A pair of U.S. space probes designed to provide detailed information about the outer regions of the solar system.
 The rings of Saturn. The units are Saturn radii (Rs), which are a unit of distance equivalent to the radius (half the diametre) of Saturn. One Saturn radius is approximately 60,500 km.
Tethys
E-ring thickness
30,000 km 20,000 km 10,000 km
0km 10,000 km 20,000 km 30,000 km
Not shown:
Pan (2.22R s)
Atlas (2.28 Rs) Prometheus (2.31 Rs) Pandora (2.35 Rs)
Titan (20.3 Rs) Hyperion (24.6 Rs) Iapetus (59.1 Rs) Phoebe (214.9 Rs)
Voyager 2 (6.3 Rs) Dione
Rhea
E-ring
56789
45