The term ‘Equinox’ corresponds to an astronomical event that occurs twice a year when the sun is positioned directly above the earth’s equator. These events typically take place around the 21st of March and the 23rd of September. An equinox is characterized by an equal duration of day and night time in both the Northern and Southern Hemispheres.
Duality of Vernal and Autumnal Equinoxes
There are two types of equinoxes, known as the vernal (spring) equinox and the autumnal equinox. The vernal, or spring, equinox transpires for the Northern Hemisphere around the 20th or 21st of March, while it occurs for the Southern Hemisphere on the 22nd or 23rd of September. On the other hand, the autumnal equinox takes place during the autumn season in the Northern Hemisphere on the 23rd of September. This occurrence correlates with the advent of spring in the Southern Hemisphere. A reverse of these events is observed on the 21st of March.
The Significance of the Equinox
The equinox holds much significance as it is when the sun is located directly above the equator, resulting in almost equal amounts of sunlight being received by both hemispheres. Following the spring equinox, the Northern Hemisphere gradually tilts closer to the sun, which leads to longer daylight hours consisting of earlier sunrises and later sunsets in March.
In Hindu astrology, the vernal equinox is referred to as Vasant Vishuva or Vasant Sampat. The spring equinox witnesses the blooming of plants, earlier sunrises, and later sunsets in the Northern Hemisphere. Meanwhile, the Southern Hemisphere experiences later sunrises, earlier sunsets, cooler winds, and the drying and falling of leaves.
Equinox and UPSC Civil Services Examination
The understanding of the equinox concept often comes in handy for competitive examinations like the UPSC Civil Services Examination. To provide an example, a question was asked in the previous year’s examination on the subject. The question sought to understand when the longest day of the year usually occurs in the Northern Hemisphere. It was given in the format of multiple choices, with the correct answer being the ‘second half of June (21st June).’
Understanding the equinox phenomenon is paramount because it offers insights into the earth’s rotation and revolution patterns. It significantly contributes to the study of geography, environmental science, climate change, and even astrology. It aids in predicting weather conditions, understanding the change of seasons, and forecasting natural calamities. The comprehension of such concepts often proves beneficial not only for academic pursuits but also for everyday life.
