Rhea

Saturn IV

Rhea Facts

• Rhea is the fourteenth of Saturn's known satellites and the second largest:
  • distance from Saturn: 527,040 km
  • diameter: 1530 km
  • mass: 2.49e21 kg

• Pronounced "REE a".

• In Greek mythology Rhea was the sister and wife of Cronus (Uranus) and the mother of Demeter, Hades (Pluto), Hera, Hestia, Poseidon (Neptune), and Zeus (Jupiter).

• Discovered by Cassini in 1672.

• Though somewhat larger, Rhea is otherwise very similar to Dione. They both have similar compositions, albedo features and varied terrain. Both rotate synchronously and have dissimilar leading and trailing hemispheres.

• Rhea is composed primarily of water ice with rock making up less than 1/3 of its mass.

• On the trailing hemisphere there is a network of bright swaths on a dark background and few visible craters (picture 4).

• The leading hemisphere is heavily cratered and uniformly bright (picture 1, above). Like Callisto, the craters lack the high relief features seen on the Moon and Mercury.

• Rhea's history is probably very similar to Dione's.

Pictures

1. (above) Rhea 65k gif

2. section of Rhea 74k gif; 82k jpg

3. Rhea in computer enhanced color 54k jpg

4. Trailing side 54k gif

5. Color close up 558k gif

6. Rhea, moon of Saturn, beginning of pass 143k gif
7. Rhea, moon of Saturn, getting closer 180k gif
8. Rhea, moon of Saturn, closer, good detail 225k gif
9. Rhea, moon of Saturn, closer, darker image 374k gif
10. Rhea, moon of Saturn, closest approach 416k gif
11. Rhea, moon of Saturn, receding, good detail 396k gif
12. Rhea, moon of Saturn, receding, good detail 317k gif

More about Rhea

• from LANL

Open Issues

• Rhea and Dione seem almost identical yet Rhea is twice as massive. Why are they so similar?