What is Iapetus (moon)?
[[Image:Iapetus 706 1419 1.jpg|right|thumb|Iapetus, photo taken by [[Cassini-Huygens]]]] '''Iapetus''' is a large [[Satellite (natural)|moon]] of [[Saturn (planet)|Saturn]]. It was discovered by [[Giovanni Domenico Cassini]] in 1671.<ref name=cox>{{cite book|author1=Cox, Brian|author2=Cohen, Andrew|title=Wonders of the Solar System|date=2010|publisher=HarperCollins|page=94-95|isbn=9780007386901}}</ref> 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.<ref name=cox /> 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 [[equator]]ial ridge discovered by the [[Cassini-Huygens]] spacecraft on 31 December 2004. Iapetus has a slow rotation rate, taking 79 [[Earth]] days for a rotation.<ref name=cox /> Another observation that has puzzled scientists is how it has a [[mountain range]] across its equator, giving it the shape of a [[walnut]]. ==References== {{reflist}} <br />{{Moons of Saturn}} {{sci-stub}} [[Category:Saturn's moons]]