Discovery
Iapetus was discovered by Giovanni Domenico Cassini, an Italian-born French astronomer, in October 1671. This is the first moon that Cassini discovered; the second moon of … See more

The moons of Saturn are typically thought to have formed through co-accretion, a similar process to that believed to have formed the planets in the Solar System. As the young gas … See more

The low density of Iapetus indicates that it is mostly composed of ice, with only a small (~20%) amount of rocky materials.
Unlike most of the … See more

The monolith featured during the climax of Arthur C. Clarke's 1968 novel 2001: A Space Odyssey is located on Iapetus.
A team of scientists explore Iapetus in The Saturn Game, … See more

The orbit of Iapetus is somewhat unusual. Although it is Saturn's third-largest moon, it orbits much farther from Saturn than the next closest major moon, Titan. It also has the most inclined orbital plane of the regular satellites; only the irregular outer satellites like See more

The first spacecraft to visit Saturn, Pioneer 11, did not provide any images of Iapetus and it came no closer than 1,030,000 km (640,000 mi) from the moon. Nonetheless, Pioneer 11 was humanity's first attempt to obtain direct measurements from the objects within the … See more

• Iapetus seemingly in the shape of the famous Taijitu (also known as the Yin-Yang symbol). This was imaged by Voyager 1 on … See more