Students stand under the sun casting negligible shadows on the 'Zero Shadow Day' at Jawaharlal Nehru Planetarium, in Bengaluru on August 18, 2023.
Credit: PTI File Photo
Bengaluru on Wednesday witnessed a ‘Zero Shadow Day’, between 12:17 pm and 12:23 pm, when shadows of people vanished for a short period of time during the phenomenon.
The Indian Institute of Astrophysics Bengaluru had earlier posted on X, informing about the the celestial event.
Bengaluru experiences this unusual phenomenon twice a year— one around April 24/25 and the other on August 18.
The Zero Shadow Day is a rare phenomenon that takes place twice a year in locations situated between +23.5 and -23.5 degrees latitude, as stated in the ASI website.
“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. This Zero Shadow Day will clearly be different for different places on earth,” the ASI website mentions.
The Astronomical Society of India (ASI) explains this occurrence saying that when the sun is directly at the zenith position, it doesn't cast a shadow on any object, thus shadows of all objects and living beings disappear during this event.
Zero Shadow Day is usually witnessed twice in a year in areas situated between the Tropic of Cancer and the Tropic of Capricorn. This phenomenon occurs mostly in locations near the Equator, during the equinoxes where the Sun passes directly overhead.