Hi Ken B,

You are confusing 'zeinith' with 'meridian passage' (or culmination) of a celestial object.

The zenith is the point directly above an observer. It is a point on the meridian at altitude 90 deg., (and only at that point).

The meridian is an imaginary line looping from north to south i.e. the great circle (longitude) passing over the observer's head.

When an object is said to be at the zenith, it can only be at a point on the meiridian with altitude 90 deg.

When an object is said to be on the meirdian, it can be on any point between zero altitude and 90 deg. altitude.


Seen from Giza, neither the sun nor Orion were (oe ever will be) at zenith. The maximum altitude the sun can have at meridian is at summer solstice which, as seen from Giza, would be 84 deg. (thus 6 deg. away from the zenith). As for Orion's belt, it's maximum altitude at meridian will be 60 deg.

In the Pyramid Age Orion's belt culminated at the south meridian every 24 hours at about 45 deg.

The sun culminated at 45 deg. twice a year. The days when these occured do not have any particular significance.

RB