Spring Equinox 2017 | Texas Public Radio

Spring Equinox 2017

Mar 21, 2017

  

The Earth at the Spring Equinox
Credit NASA

  

March 20 was the first day of Spring.  And other than promises of wildflowers and Spring allergies, the Equinox brings with it an astronomical event that only happens twice a year. 

Nicholeen Viall is a research astrophysicist with NASA.  She explains why the equinox is so unique.  “Yeah, so Equinox means in Latin 'equal day and equal night,' and that’s exactly what happened today.  The day and the night are of equal length, and that only happens twice a year – the Fall Equinox and the Spring Equinox.”

And that applies to all points on the globe.  And have you wondered why our days are longer in the Summer and shorter in the Winter?  Viall says “Because of the Earth’s rotational tilt relative to its orbital path around the sun, one of the hemispheres will be differently illuminated than the other hemisphere.  So when the Northern Hemisphere is pointed toward the sun, that’s our summertime, and we have longer days and shorter nights.  Conversely, when we’re pointed away from the sun, that’s our wintertime and we have long nights and short days. “

And…no… you can’t balance an egg on its end only on the equinox.  Scientists say if you try hard enough, you can balance it any day of the year.

 Spring officially began Monday at 5:29 a.m.  We’ll see our days gradually get longer until the first day of Summer, June 21st…in 93 days.