As I peddle the EQ concept I am often astonished to discover how hazy is the concept of equinox. I have used this NASA image as background for new Facebook and Twitter pages as it clearly shows – in a real image from space – Earth at equinox. This clarifies that it’s the moment when the Equator is exactly parallel to the plane of the Ecliptic – the imaginary plane containing the Earth’s orbit around the sun.
Because the Earth’s axis is tilted 23.5º to this plane, giving us our hemispherical seasons (tilt away from the sun=winter, towards=summer), equinox only happens when the tilt is cancelled out on this annual orbital journey. Spring or Vernal Equinox is on 20th or 21st March, Autumn Equinox on 22 or 23 September. Equi-nox of course means Equal Night – because at equinox exactly half the planet is dark, half in the light. The excellent website Time and Date will give you the moments of equinox (and solstice) for your town – plus copious information on all things temporal and planetary.
The logical extension from this is that all life on earth has a shared moment of equality at equinox, literally and metaphorically. Which is why EQ has the strapline Equal under the Sun and acquired the .org website