Zero Shadow Day: Bengaluru locals took to social media to share pictures of the celestial event.

Bengaluru, the city known as the Silicon Valley of India, witnessed a rare celestial phenomenon called “Zero Shadow Day” on April 25th, which took place at 12:17 p.m. when there was no shadow from sunlight.

“Zero Shadow Day” occurs when the sun doesn’t throw a shadow on a vertical object. Several local citizens and students witnessed this moment in open places.

Locals from Bengaluru posted photos taken on “Zero Shadow Day” to social media.

Scenes from @azimpremjiuniv on Zero Shadow Day. @arjun_jayadev@_an_i_sh_@kripadotgpic.twitter.com/DvTK80BPVd

— Physics@Azim Premji University (@HandsOnPhysics) April 25, 2023

Photo clicked at exactly 12:17 pm. Shadow clearly visible. 😐#ZeroShadowDaypic.twitter.com/oCkBt1Pr3u

— Sitting Duck ‏‎‎‎سميت 🇮🇳 (@S_erendipits) April 25, 2023

all vertical objects in the city were shadowless at 12:17 pm! It occurs twice a year when the sun 🌞 is exactly overhead #zeroshadowday#Bengalurupic.twitter.com/Q6BhxPSdha

— Yash is hiring! 🇮🇳 (@yashodhannn) April 25, 2023

What exactly happens on “Zero Shadow Day“?

Zero Shadow Day is a phenomenon that occurs twice a year, where the Sun’s position is directly overhead, casting no shadows on the Earth’s surface. So, at 12:17 pm, any vertical object will cast no shadow in Bengaluru. 

During Zero Shadow Day, the sun reaches its highest point in the sky resulting in the reduction of the length of the shadow. When we stand on this shadow, our own shadow becomes invisible, hence the term “Zero Shadow”.

“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,”  Astronomical Society of India noted.

Explaining the phenomenon, astrophysicist Debiprosad Duari told PTI, “People and any object, all around the world, staying between the Tropic of Cancer and Tropic of Capricorn lose their shadows, though momentarily, twice a year. These two moments are called zero shadow moments.”

Every year on the zero shadow days, students and astrophile who are located between the two Tropics erect vertical poles, and different objects, and sometimes even stand outside to see for themselves the cosmic event. The moment can be witnessed without any special equipment or instruments.

The next Shadow Day in Bengaluru will be observed on August 18. The dates of Zero Shadow Day vary depending on the location and time zone.