When days and nights are equal on the equator, this natural phenomenon is called equinox. This term has been derived from Latin language-Aequus which means equal while nox means night, as during the course of equinox, the length of both the night and the day is approximately equalized. It usually occurs two times a year i.e. 21st march and 23rd September. The sun is at right at the top of two intersections points between the celestial equator and the ecliptic during the course of equinox. The sun pours down direct light on northern hemisphere causing shorter days for the first six months, the period of winter and this starts with a spring equinox. And on the next 6 months, during the summer season and longer days, the sun pours more intense light on the southern hemisphere and this season is started by autumn equinox. But on the mentioned dates, the length of days and nights are equalized and this whole process is termed as equinox.


March 2, 2011 | Khadija Afzal | 1 Comment | 419 views