歳さい差さ

noun

precession of the equinoxes

Technical astronomical term referring to the gradual shift in the orientation of Earth's axis, causing the equinoxes to move westward along the ecliptic.

• 歳さい差さの周しゅう期きは約やく2万まん6000年ねんです。

  The cycle of the precession of the equinoxes is about 26,000 years.