EVERYDAY SCIENCE

Detailed explanation-1: -On Earth, there are two equinoxes every year: one around March 21 and another around September 22. Sometimes, the equinoxes are nicknamed the “vernal equinox” (spring equinox) and the “autumnal equinox” (fall equinox), although these have different dates in the Northern and Southern Hemispheres.

Detailed explanation-2: -The autumnal equinox-also called the September equinox-arrived on Thursday, September 22. This date marks the start of fall in the Northern Hemisphere and spring in the Southern Hemisphere.

Detailed explanation-3: -The September equinox (or southward equinox) is the moment when the Sun appears to cross the celestial equator, heading southward. Because of differences between the calendar year and the tropical year, the September equinox may occur anytime from September 21 to 24.

Detailed explanation-4: -In the Northern Hemisphere, the spring equinox, or vernal equinox, occurs around March 21, when the sun moves northward across the celestial equator. The autumnal equinox occurs around September 22 or 23, when the sun crosses the celestial equator going south. In the Southern Hemisphere, it’s the reverse.