Glossary Z

Zenith: The point on the sky directly above an observer (that is 90 degrees above the observer’s horizon).

Zodiac: A band around the celestial sphere, on either side of the ecliptic, through which the Sun, Moon and naked-eye planets appear to travel.

Zodiacal Light: A faint cone-shaped  glow that extends along the ecliptic from the western horizon after sunset or from the eastern horizon before sunrise.