Bengaluru to witness 'Zero Shadow Day' today. See time, other details

When the sun is directly at the zenith position, it doesn't cast a shadow on any object and this can be observed between 12:17-12:23 pm in Bengaluru today.

Bengaluru is poised to experience a remarkable celestial event known as 'Zero Shadow Day' on Wednesday, during which all vertical structures in the city will briefly cast no shadow. The event is scheduled to occur at 12:17 pm local time and the effects can be observed till around 12:23 pm.

The phenomenon occurs two times a year in places located between +23.5 and -23.5 degrees latitude. (HT Photo)

In light of this occurrence, the Indian Institute of Astrophysics (IIA) situated in Bengaluru's Koramangala area plans to commemorate the occasion by hosting various activities on its campus. "Join us on 24 April to celebrate #ZeroShadowDay #ZSD for locations at #Bengaluru latitude. Measure shadow lengths & check out our cool demos! We will work with Bhopal & Chennai to calculate Earth's diameter and rotation speed!" The IIA posted.

What exactly is Zero Shadow Day?

It's a rare celestial phenomenon that happens twice a year in locations situated between +23.5 and -23.5 degrees latitude. During this event, shadows of all objects and living beings disappear when the sun reaches its highest point in the sky. According to the Astronomical Society of India (ASI), when the sun is directly at the zenith position, it doesn't cast a shadow on any object.

"For people living between +23.5 and -23.5 degrees latitude, the Sun's declination will be equal to their latitude twice - once during Uttarayan and once during Dakshinayan. On these two days, the Sun will be exactly overhead at noon and will not cast a shadow of an object on the ground," explains the ASI on its website.

This phenomenon occurs when the Sun's declination matches the latitude of the location. Though the alignment lasts only momentarily, its impact can be observed for up to two minutes.

Bengaluru has seen zero shadow days on April 25 and August 18 last year.