Final answer:
The term equinox translates as "equal night," which makes sense from an astronomical point of view because on the equinox, day and night are approximately equal in length. This occurs twice a year, around March 21 and September 21.
Step-by-step explanation:
The term equinox translates as "equal night," which makes sense from an astronomical point of view because on the equinox, day and night are approximately equal in length. This occurs twice a year, around March 21 and September 21. On these days, the Sun is positioned on the celestial equator, which is the projection of Earth's equator onto the celestial sphere.
From Earth's perspective, the Sun appears to be directly above our planet's equator during the equinox, resulting in roughly 12 hours of daylight and 12 hours of darkness in most places.