Sonnenmitte

Sonnenmitte is a term used in astronomy and related fields to describe the point in the sky directly overhead an observer at a specific location. It is the zenith, the point that is diametrically opposite to the nadir. When a celestial object, such as the Sun, reaches its Sonnenmitte, it is at its highest point in the sky for that observer's location. This event is significant as it marks the moment of solar noon.

The precise time of solar noon, and therefore the Sun's Sonnenmitte, can vary slightly from local clock time due to factors like the observer's longitude within their time zone and the Equation of Time. The Equation of Time accounts for the Earth's elliptical orbit and its axial tilt, which cause the apparent solar day to be slightly longer or shorter than 24 hours on many days of the year. Therefore, solar noon does not always coincide with 12:00 PM on a clock.

For observers in the Northern Hemisphere, when the Sun reaches its Sonnenmitte, it is at its highest point in the southern part of the sky (unless the observer is very close to the equator, in which case it could be directly overhead). In the Southern Hemisphere, the Sun at Sonnenmitte will be in the northern part of the sky. The altitude of the Sun at Sonnenmitte depends on the observer's latitude and the time of year (specifically, the Sun's declination). At locations on the equator, the Sun can be directly overhead (at the zenith) at certain times of the year.