When it reappeared on the west side again, Cassini realized that Iapetus must be darker on one side than the other, which made it harder to see when the dark side was facing Earth. More than 300 ...

New photos from the Cassini spacecraft reveal the splotches are mainly found on the sunward-facing ... the front probably comes from one of Saturn’s other moons and simply splattered on Iapetus ...

While many ideas abound concerning what causes this ridge, no one theory is the clear front-runner. There are many ways in which Iapetus is unusual for our Solar System, and there are quite a few ...

The moon might have slowly wandered through the ring plane, and accreted all the ring material, like snow piling up in front of a plow. A third is that Iapetus was smashed into by a massive ...

Astronomers think dark material was originally deposited on Iapetus’ front side as it slammed through carbon-rich dust thrown off Saturn’s other outer moons when they were pummeled by meteors.