Thursday is the first day of spring, or the vernal equinox, in the Northern Hemisphere. During an equinox, the center of the sun is on the same plane as the equator. After the vernal equinox in March, the Northern Hemisphere tilts toward the sun until the June solstice, when the sun begins to migrate back south.

The March equinox has captivated human civilization for thousands of years, and it has even been tied to ancient mysteries -- yet there are still many misconceptions around the changing of the season.