, and different types of Horizon. Note that the Zenith is opposite the Nadir.]]In broad terms, the zenith is the direction pointing directly above a particular location (perpendicular, orthogonal). Since the concept of being above is itself somewhat vague, scientists define the zenith in more rigorous terms. Specifically, in astronomy, geophysics and related sciences (e.g., meteorology), the zenith at a given point is the local vertical direction pointing away from the direction of the force of