Celestial marvel approaches: Zero Shadow Day to enchant Bengaluru today; here's all you need to know

Experience the celestial wonder of Zero Shadow Day in Bengaluru on August 18. Witness the sun's zenith, causing shadows to vanish in a unique astronomical phenomenon. Learn about the significance and science behind this event.

Bengaluru city is gearing up to witness a unique celestial event known as Zero Shadow Day on August 18. This extraordinary phenomenon, previously observed on April 25 in the same location, is typically experienced within areas situated between the Tropic of Cancer and the Tropic of Capricorn.

At 12:24 pm, a timing meticulously determined by astronomer Alok Mandavgane, the city is poised to encounter a celestial moment. During this fleeting instance, the Sun will be positioned precisely overhead.

What is Zero Shadow Day?

Zero Shadow Day is an exceptional celestial occurrence that takes place biannually in regions spanning from +23.5 to -23.5 degrees latitude. During this phenomenon, the sun reaches its zenith, leading to the absence of shadows cast by both objects and individuals.

As defined by Britannica, declination refers to the angular measurement of a celestial body's distance from the celestial equator, either north or south. In contrast, as clarified by National Geographic, latitude denotes the measurement of distance north or south of the Equator. This measurement is determined by the imaginary lines, called parallels, encircling the Earth parallel to the Equator in an east-west orientation.

What happens on a Zero Shadow Day?

On Zero Shadow Day, the sun aligns directly overhead, causing shadows to vanish from the Earth's surface. This alignment propels the sun to its zenith in the sky, resulting in significantly shortened shadows that essentially become imperceptible.

What to expect on this day?

According to the Astronomical Society of India (ASI), when the sun reaches the zenith position, it refrains from casting shadows on any object. For individuals residing between +23.5 and -23.5 degrees latitude, a special alignment occurs twice a year during Uttarayan (Northern Solstice) and Dakshinayan (Southern Solstice). At precisely noon on these specific days, the sun's declination matches the observer's latitude. This results in the sun being directly overhead and casting no shadows on objects at ground level.

Similarly, Hyderabad recently experienced its Zero Shadow Day on August 3 at 12:23 pm. During this instance, the sun was positioned directly overhead, temporarily causing shadows of vertical objects to disappear. Notably, Hyderabad had previously observed its Zero Shadow Day on May 9 earlier in the same year.