Autumnal Equinox 2025

Autumnal Equinox 2025. Autumnal equinox — is an astronomical phenomenon, when the sun in its visible motion along the ecliptic crosses the celestial equator. At the september equinox, the sun is moving from north to south as it crosses above the equator.

Autumnal equinox — is an astronomical phenomenon, when the sun in its visible motion along the ecliptic crosses the celestial equator. At the september equinox, the sun is moving from north to south as it crosses above the equator.