As the Northern Hemisphere welcomes spring today, the Southern Hemisphere is marked with the first day of autumn.

This event signals the start of Spring in the Northern Hemisphere and Autumn in the Southern Hemisphere, a transition that also manifests in our evening skies as winter constellations start to vanish.

It will see the transition from winter to spring as the Sun crosses the celestial equator. On this day, the length of day and night aren’t precisely equal, NASA says. The date for that split depends ...

We have officially passed the vernal equinox. The sun has crossed the celestial equator, bringing near equality to day and ...

Either of the two points in the sky where the ecliptic (the Sun’s annual pathway) and the celestial equator intersect. The vernal equinox falls about March 20 or 21 in the Northern Hemisphere ...

The spring equinox, also called the March equinox or vernal equinox worldwide, occurs when the sun travels across the celestial equator, moving south to north. Per the Old Farmer's Almanac ...