FULL MOONS A full moon is a lunar phase that occurs when the Moon is on the opposite side of the Earth from the Sun. More precisely, a full moon occurs when the geocentric apparent (ecliptic) longitudes of the Sun and Moon differ by 180 degrees; the Moon is then in opposition with the Sun. Lunar eclipses can only occur at Full Moon, where the moon's orbit allows it to pass through the Earth's shadow. Lunar eclipses do not occur every month because the moon usually passes above or below the … [Read more...]