Tomorrow we wake up to a new season. Spring begins at 3:44 p.m. MDT— the moment of the vernal equinox. It occurs when the Sun crosses Earth’s equator from south to north. We look forward to longer and warmer days.
The equinoxes are also the only times of year when the Sun rises due east and sets due west. Equinoxes occur because the axis of the Earth is tilted at an angle of 23.5° This axis tilt remains fixed as it circles around the Sun. For part of year, the Earth's north pole is tilted towards the Sun (in June), at other sometimes it is tilted away from it (in December). This gives rise to the Earth's seasons: The Spring and Fall Equinoxes come halfway between. Both hemispheres experience roughly equal amounts of daylight and darkness.
The name “equinox” means “equal nights.” Coincidently the 2019 March full moon rises on the Vernal Equinox. This March Full Moon is also a supermoon. It’s the year’s third (and final) of three straight full supermoons. The March Full Moon is called the Full Worm Moon. As the ground warms earthworms reappear, where birds begin to feed/ This is the final full moon of winter.