Something non-technical Equinox

The phenomenon of equinox could be understood by developing some insight into our solar system. We all know that the earth undergoes two types of motion namely the revolution around the sun and rotation about its own axis.
The earth revolves in an elliptical orbit around the sun. But the equatorial plane of the earth is not the same as that of the elliptical plane in which the earth revolves around the sun. The earth's rotational axis is tilted by an angle 23.5° with respect to its orbital plane. If the earth’s equatorial plane is extended into the space, it is known as the celestial equator in the scientific language.

The imaginary plane containing the earth’s orbit around the sun is known as the ecliptic plane. The celestial equator in space intersects the ecliptic plane at two points. In case of Spring Equinox, the Sun lies on one of the points where the ecliptic and celestial equator intersect.
On this day, the Sun travels across the sky along the celestial equator northwards. On autumnal equinox the Sun again lies on the ecliptic and celestial equator at the second place where they intersect, this time heading southwards for the winter.

There is a significant fault in western astrology where the periods of vernal equinox are said to fall in Aries (March 21 - April 19). But it currently falls between Pisces and Aquarius. Same is true about the autumnal equinox, which now actually should be in Virgo instead of proclaimed Libra (September 22 - October 22).
This is due to the western astrologers following the solar system. Indian astrology is free from this defect because of being based upon the lunar system.

Modern astronomy aside, people have recognised the vernal equinox for thousands of years. There is no shortage of rituals and traditions surrounding the coming of spring.

The date is significant in Christianity because Easter always falls on the first Sunday after the first full moon after the vernal equinox. It is also probably no coincidence that early Egyptians built the Great Sphinx so that it points directly toward the rising Sun on the day of the vernal equinox.

There are some folklores and superstitions attached to the event like the one about balancing eggs on their ends during the Equinox; it is outright unscientific. The event is certainly of importance in meteorological studies but has no negative effect on earth’s atmosphere. It is just as usual an event as occurrence of usual days and nights.

courtesy: Sify