Ostara: Some Science

The Vernal Equinox occurs on March 19 at 11:06 pm EDT. But does the Spring Equinox usually occur on the 21st? Well, it used to. The last time the Spring Equinox was on the 21st was in 2007. Due to a shift in the calendar, it won’t be on the 21st again until the 22nd Century! In the next 3 years it will occur on March 20.

When does Spring begin? It depends on what line of thought to which you subscribe. According to the Celts that day is February 2 or Imbolc. Meteorological spring begins on March 1, and many meteorologists peg that as the date. The Vernal Equinox is also considered to be the first day of spring. So, you decide!

Are the day and night equal lengths? Almost. Day officially begins when the sun just peeks over the horizon and ends when the sun has fully set beyond the horizon. This is a fairly arbitrary rule. The sun is not a point but a sphere, and as such it takes time for this sphere to rise and set over the horizon. Atmospheric refraction can add apparent daylight. Therefore on the Vernal Equinox day is just a tad longer than night.

The sun rises and sets due East and due West respectively on the Equinoxes only. No matter where in the world you live this works except for the poles. Go out and check the position of the sun on the horizon and you can work out the four directions where you live. I like to put up a marker such as a small cairn to indicate due East or West.

In midday how high in the sky is the sun on the Vernal Equinox? It depends on your latitude. The sun rises the same number of degrees into the sky as the latitude on that day. For example let us say that you live in Chicago, IL. The latitude of Chicago is 41.8781 degrees North. That’s approximately 42 degrees so let us call that 42. In Chicago the sun will be 42 degrees high which is a little less than halfway from the horizon to straight overhead. So just find out the latitude of the place you live and that will be how high the sun will be on this day.


Can you balance an egg on end on the Equinox? You can, but it does help to have a rough surface on which to balance it. An egg can be balanced on end on other days as well. It is more of a fun thing to do on Ostara.

Did you notice that worms and grubs start to appear this time of year? Yes, March is the month of Worm Moon. Migratory birds like robins start to fly north. One of their favorite prey is worms which they locate by hearing.

Just like we shed our winter coats about this time of year, so do many mammals residing in your area. If you have a dog or cat, you know what I mean. Fur gets everywhere!

Take a walk and see what you observe as the Wheel turns!

Have a meaningful and happy Ostara!

Auburn Greene

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