Bengaluru is set to observe a Zero Shadow Day once again on August 18. This rare celestial occurrence was earlier observed on April 25 in Bengaluru and it usually occurs between regions that are located between the Tropic of Cancer and Tropic of Capricorn.On Zero Shadow Day, the sun remains directly overhead, and no shadows will be formed on the earth’s surface. This means that the sun reaches its highest point in the sky which results in the reduction of the length of the shadow to the extent that it is no longer visible.
Zero shadow day is a special celestial event that occurs twice a year at places between +23.5 and -23.5 degrees latitude. During this event, the sun is at its highest point in the sky, resulting in the absence of the shadow of any object or a person.

According to the Astronomical Society of India (ASI), the Sun will not cast a shadow on an object – when it is exactly at the zenith position. In its website, the ASI wrote, “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.”