Question

What term describes the alignment of three celestial bodies?

Answer 1

In astronomy, a syzygy (from the Ancient Greek,meaning "yoked together") is a straight-line configuration of three celestial bodies in a gravitational system.

The word is often used in reference to the Sun, Earthand either the Moon or a planet, where the latter is in conjunction or opposition. The term is often applied when the Sun and Moon are in conjunction (new moon) or opposition (full moon).