Eclipse

Eclipses occur when the Sun, Moon, and Earth precisely line up. The Moon, in its orbit around the Earth, is inclined at about 5 degrees to the ecliptic (the plane at which the Earth orbits the Sun). Therefore the Moon spends most of its time above or below the ecliptic plane. The Sun must be at a precise location too. Since the Sun travels an apparent path around the celestial sphere once per year, eclipses are possible only at roughly six-month intervals.