Meier has a single moon. It figures prominently in many religious and cultural traditions.
According to modern astronomical understanding, the moon is a spherical body with a radius of precisely 1/3 Meier’s radius, which completes a single orbit of Meier every 30 days exactly. Over the course of these 30 days, it undergoes a series of phases depending on which part of the moon is lit: three nights of new moon (dark), twelve nights of waxing (getting more light from right side each night), three nights of full moon (completely lit), and twelve nights of waning (getting darker from right side each night). The Occidental Calendar is lunar-based: the night of the first day of each month is always the second night of new moon.
The moon’s rotation is a bit out of sync with its revolution, meaning that the moon is seen at a slightly different angle at each full moon. It takes 36 years for the moon to complete a full rotation (relative to Meier). The rotational positions of the moon relative to Meier are called aspects, and they play an important role in lunar astrology (see below).
Powerful wizards have visited the moon, and reported it to be devoid of any atmosphere or life. It does have hills, mountains, ridges, valleys, and craters, and at least one lake of ice. These features are also visible from Meier using visual aids such as a telescope.
The moon figures centrally in various religious and cultural traditions. It is understood to be a powerful nexus of spiritual power, and possibly a gateway to another plane.
Hiropeh is a goddess of the moon. In the simplest sense, the moon is seen as an eye of Hiropeh, shining down on anyone who would use the darkness as a cover for their wickedness. The moon is also said to be the personal domain of Hiropeh in some teachings. Some Hiropean clerics feel stronger connections to their goddess or enhanced powers during nights of the full moon, and others experience mystical visions during new moons.
Avatrunei’s faith also claims the moon, although it goes a step further in claiming that the god actually created the moon. In particular, it is said that Avatrunei ordained that the moon should have phases and aspects.
There is also a moon goddess called Aulu who is completely unknown in the Old World, but receives prayer from a number of New World fey.
There is a minor controversy between astronomers and astrologers about the inside of the moon. Most astrologers, have long believed that the moon was another plane of existence. But wizards have visited the surface of the moon, and it is definitely part of our plane, the Material Plane. Astrologers revised their claims, saying that the inside of the moon is another plane (or a gateway to another plane). Some arcane astrologers have tried teleporting to the inside of the moon, but are unable to. The most likely explanation, they say, is that the moon is solid. Astrologers counter that the inside of the moon, being a planar portal, is blocked from normal teleportation, and additionally it’s possible the wizards haven’t tried teleporting deep enough into the center of the moon. Eustace once fought a minor war with a neighboring duchy over this topic, but the Emperor of Gard quickly put a stop to it.
The moon rotates slowly with respect to its orbit around Meier. To a viewer on the planet, the moon appears to complete one rotation every 36 years. The ancient Idiyans recognized various shapes and figures, called aspects, in the surface of the moon, and derived a lunar horoscopic system based on these aspects – the same system is in use throughout Occident today. It is possible to determine the current aspect by dividing the current year by 36 and comparing the remainder to the following chart. (For example, this year, 471 OC, is in the aspect of the sword.) The aspects are: