How do we know precession is happening?

1 Answer
Feb 28, 2016

The precession of equinox-instant by about 20'23" / year reveals that there is precession of poles, with period 25810 years, nearly..


Equinox is the instant at which noon-Sun, at latitude 0 ( some location in the equator ), will be exactly overhead.
The poles revolve about a mean position once ia Great Year of nearly 258 centuries.