Today, September 23rd at 7:51am, Sun reached Zero
declination, if we observe Sun’s position at Equator on this day, we will see
Sun will be exactly overhead at noon. In coming days if we keep observing the
Sun’s position we will notice that Sun is moving towards south with each
passing day. Sun will reach southernmost point on December 21st.
Sun reaching the Zero declination point is called Equinox.
This happens twice in a year; first one will be on March 20/21 and second will
be on September 23rd.
From March, the Sun will be in northern hemisphere of the
sky reaching northern most point on June 21st at 23.50
and returning to Zero declination in September. From September Sun will be in
Southern hemisphere of the sky reaching extreme south point of -23.50
on December 21st , from December Sun will start moving towards north
and reach Zero declination on March 21st .
March Equinox is called Vernal Equinox and
September Equinox is called Autumnal Equinox.
