Morrslieb and Mannslieb
The Warhammer world has two moons. The larger of these – known as Mannslieb, the silver moon (named for the god of the seas) – has a cycle of 25 days from full to full, and looks not unlike the moon of our world. Morrslieb, the Chaos moon, is named after the god of death. Its phases and movements defy all attempts to predict or explain.
There are two main legends concerning the origins and nature of Morrslieb. According to the first, it was once a gateway in the sky, through which daemons came to prey upon the people of the Known World. Morr inflicted a great and terrible death upon them and fashioned the second moon out of the wreckage, so that mortals would never forget how the god had saved them. The second legend maintains that when Chaos first broke through into the Known World, a great block of warpstone was hurled high into the sky, where it now circles endlessly, spreading Chaos on the lands over which it passes. This legend is believed mainly by followers of Chaos who hold festivals when Morrslieb is full.
The truth remains a mystery.