Zenith
In the celestial coordinate system, point directly over the observer (elevation of 90º). Nadir would be the opposite point, exactly below the observer (-90º elevation). Time and Date
Zodiacal constellations
The zodiac constellations are the 13 constellations on the Earth’s ecliptic. The thirteenth constellation, often forgotten, is Ophiucus.
Zodiacal light
The starlight or false dawn is a rare optical effect that occurs before sunrise or after sunset, usually at the beginning of spring or late autumn and is a triangular-shaped light band that is especially appreciated in the night sky. It extends along the ecliptic plane and in the direction of the sun. Caused by dust particles scattered in the solar system. Time and Date