Eclipses

Lunar eclipses are occultations of the Moon by the shadow of the Earth, while solar eclipses are occultations of the Sun by the shadow of the Moon. These celestial concordances are frequently observed, at least one of each (lunar eclipse or solar eclipse) every 6 months.
Eclipses take place at syzygies, that is to say when there is a quasi alignment between the Sun, the Earth and the Moon. The solar eclipse takes place at the new moon, the lunar eclipse takes place at the full moon.