Syzygy (astronomy) - Wikipedia
https://en.wikipedia.org/wiki/Syzygy_(astronomy)The word is often used in reference to the Sun, Earth, and either the Moon or a planet, where the latter is in conjunction or opposition. Solar and lunar eclipses occur at times of syzygy, as do transits and occultations. The term is often applied when the Sun and Moon are in conjunction (new moon) or opposition (full moon). The word syzygy is often used to describe interesting configurations of astronomical objects in g…