Fall Equinox 2024. Autumnal equinox, two moments in the year when the sun is exactly above the equator and day and night are of equal length; Also, either of the two points in the.

As september 22nd approaches, we find ourselves on the cusp of a celestial event that has captivated humans for millennia: Autumn equinox 2024 (beginning of astronomical autumn) on the day of the autumn (september) equinox, the sun, moving along the ecliptic, crosses the celestial equator,.