Did you know that the start of Spring is marked by a fascinating celestial event? The spring equinox, which usually occurs on March 20 or 21, signifies when the sun crosses the celestial equator from south to north. On this day, something special happens. Day and night become approximately equal in length, as the sun shines directly on the equator. As you'd expect, this unique event impacts our world in several ways. In the animal kingdom, the equinox acts as a wake-up call. Birds begin their migration back north, bears come out of hibernation, and butterflies emerge from their cocoons. But it's not just the animals that celebrate the arrival of Spring. People around the world have their own ways of acknowledging this pivotal time of year. In Japan, for example, the day of the spring equinox is a national holiday known as 'Shunbun no Hi'. People visit family graves and hold family reunions to celebrate the change of seasons. So, as you can see, the spring equinox is more than just a date on the calendar. It is a global celebration, a natural wonder, and a sure sign that warmer days are just around the corner.