The First Day of Spring
The Vernal Equinox Marks the Start of Astronomical Spring
Spring begins in the Northern Hemisphere as Earth's Noth Pole tilts sunward.
The vernal, or spring, equinox occurs in March for those in the Northern Hemisphere. The equinox is so named because it provides for equal days and nights.
In the winter, the North Pole tilts away from the sun, allowing for both less sunlight and fewer direct rays of sunshine. The opposite is true in summer, when the North Pole tilts toward the sun and the Northern Hemisphere receives longer hours of sunlight and more direct rays. In between the two, the Earth tilts to provide the equinoxes, when day and night are more equal in the transitional seasons of spring and fall.
Here are the dates and times for upcoming spring equinoxes in the Northern Hemisphere:
- March 20, 2008 1:48 am EDT (March 19, 2008 10:48 pm PDT)
- March 20, 2009 7:44 am EDT
- March 20, 2010 1:32 pm EDT
- March 20, 2011 7:21 pm EDT
- March 20, 2012 1:14 am EDT (March 19, 2012 10:14 pm PDT)
- March 20, 2013 7:02 am EDT
- March 20, 2014 12:57 pm EDT
Sunrise, Sunset
On the equinox, the sun rises directly in the east and sets directly in the west, making it a great opportunity to find the cardinal directions without a compass. Ancient calendar devices, such as Mayan temple structures, marked the location of the sun during the equinoxes and solstices.
Equinox and Equality
Although equinox means "equal," the hours of sunlight and darkness are not precisely equal on this date, but they are close. A combination of the Earth's atmosphere and the large size of the sun taking time to appear above and set below the horizon skews the actual date of light and darkness equality. The true date will vary from place to place. You can check your local paper for sunrise and sunset times or the USNO web site for exact times.
Balancing an Egg
The spring equinox is occasionally close to the date of Easter. This may have been some of the reason that the vernal equinox is often tied to the ability to balance an egg on its end. The belief that the Earth is tilted just so and that all things on this one day are "equal" have brought about a myth that the balance extends even to the ability to stand an egg on its point.
While it is an amusing endeavor to try, whether or not you can do it has nothing to do with the equinox. Your luck at standing an egg on end will be the same on any day of the year.
