Iapetus

{ Moons of Saturn }

Discovered by            Giovanni Domenico Cassini
Date of Discovery        1671
Distance from Saturn     3,561,300 km
Radius                   718 km
Mass                     1.6 × 10^24 g
Orbital Eccentricity     0.02828
Orbital Inclination      14.72°
Orbital Period           79.3301825 days
Rotational Period        Synchronous
Density (gm/cm3)         ??? 

Similar to Rhea, Iapetus is an icy moon believed to have a rocky core. One of the striking things about it is its appearance. It seems to have a huge birthmark. While part of the surface is bright, like Rhea, a large area of the leading hemisphere is covered with a reddish dust. It is unknown how the dust got there or what its composition is. Theories abound.

Could it have been swept up from space when meteors struck nearby Phoebe or from some other source? Perhaps, but the dust is not similar in color to Phoebe's surface. But the fact that the coloration is only on the leading face supports this theory. On the other hand, the patterns seem to resemble the volcanic flows of our moon and Mars, in that the dust seems to concentrate at the bottoms of impact craters and other low areas. Perhaps methane or ammonia from within the satellite erupted to the surface at some point in its history.

Sources:
NASA.gov
space.com

In historical geology, this is the name given to the ocean which existed between Africa/Europe and North America prior to the formation of Pangea. This is essentially the previous incarnation of the Atlantic Ocean. The closing of the Iapetus led to the collision between North America and Africa which resulted in the Appalachian Orogeny (~ 400mya).

The rifting between Africa and North America ~ 250 mya opened the modern Atlantic.

Little is known about the geography of the Iapetus Ocean, since it was almost completely destroyed by subduction as Pangea formed. However, some island arcs were accreted onto North America, and can be found as heavily metamorphosed exotic terrains within the Appalachians.

Ιαπετος

One of the Titans, the son of Uranus (the sky) and Gaia (the earth) (Table 5). He therefore belonged to the first generation of divinities and was one of the elder brothers of Cronus. According to Hesiod he married Clymene, one of the daughters of Oceanus and Tethys, by whom he had four children, Atlas, Menoetius, Prometheus and Epimetheus. Through Prometheus, Deucalion, father of mankind, was connected with him (Table 38) after the worldwide flood. Other legends say that his wife was Asia, another of the daughters of Oceanus; others maintained that his wife was Asopis, a daughter of Asopus and granddaughter of Oceanus or even Libya. Together with the other Titans he was thrown down into Tartarus by Zeus.

{E2 DICTIONARY OF CLASSICAL MYTHOLOGY}