Iapetus is a large moon of Saturn. It was discovered by Giovanni Domenico Cassini in 1671.[1]
Iapetus is unusual: one side is very bright and the other side is very dark. This is because one half of the moon is covered in ice and the other side is coated in black, dusty carbon deposits.[1] When Cassini observed the moon, he could only see the moon on one side of Saturn. He concluded that the moon is darker on side than the other, and it was confirmed by the Voyager 1 spacecraft. Iapetus also has an equatorial ridge discovered by the Cassini-Huygens spacecraft on 31 December 2004. Iapetus has a slow rotation rate, taking 79 Earth days for a rotation.[1] Another observation that has puzzled scientists is how it has a mountain range across its equator, giving it the shape of a walnut.
References
Wikiwand in your browser!
Seamless Wikipedia browsing. On steroids.
Every time you click a link to Wikipedia, Wiktionary or Wikiquote in your browser's search results, it will show the modern Wikiwand interface.
Wikiwand extension is a five stars, simple, with minimum permission required to keep your browsing private, safe and transparent.