Why Do Lunar Eclipses Happen Not Every Month?

Once you have observed a lunar eclipse, there will be another one six months later. And the cycle will continue with a lunar eclipse occurring every six months - five or six times in a row. To understand why this is, it helps to ask why lunar eclipses don't occur every month. The orbit of the moon is slightly inclined relative to the orbit of the earth,. by about five degrees. So when the moon is full most of the time it is slightly above or below the ecliptic and therefore remains illuminated. There are two special points on the moon's path across the sky, where it intersects with the e Clippings: nodes. If the moon happens to be