Lunar libration

Forums Moon Lunar libration Lunar libration

Bill Leatherbarrow

Hi James,

Good question!

The short answer is that because of the combination of various librations (libration in longitude, libration in latitude, and diurnal libration) the cycle of librations does not map onto the Moon’s monthly cycle. A more detailed explanation will require someone with a greater grasp of celestial mechanics and maths than I possess. Perhaps someone such will be along soon!