To understand how the “wobble” of the 26,000-year-precession cycle has no noticeable effect on the Sun’s rise and set points, imagine the celestial sphere of stars that surrounds us.

The whole celestial sphere is measured in degrees. All the way around the entire sky is 360 degrees, a complete circle. The NCP is at (+) 90 degrees; the celestial equator is at 0 degrees.

In January 2025, this convergence will happen in the western sky shortly after sunset. The grouping will occur within a few degrees of the celestial sphere, making them visible together through ...

Copernican armillary sphere from set of two armillary spheres and a celestial globe constructed in paper on pasteboard with metal fitments supported on a decorative mahogany baluster base. Shows ...