Odisha residents on Friday witnessed Zero Shadow Day, a rare celestial phenomenon wherein no shadow of any object or being is observed. Generally, the event occurs twice a year when the sun remains at its peak in the sky. The event takes place when the sun comes exactly overhead over all the regions between the Tropic of Cancer and the Tropic of Capricorn. Due to this, the shadow of objects and beings almost vanish during the day and hence, it is known as Zero Shadow day. The celestial phenomenon started at 11.43 am in Bhubaneswar and continued for a brief period of 3 minutes, Odishatv.in reported. It generated enthusiasm, especially among children who are currently confined in homes amid the ongoing COVID-19 pandemic.
Deputy Director of Pathani Samanta Planetarium in Bhubaneswar, Subhendu Patnaik explained the phenomenon. According to him, the event takes place when the rotation axis of the Earth is tilted at an angle of 23.5° to the axis of revolution around the sun.
He further said that when the location of the sun moves from 23.5° N to 23.5° S of Earth’s equator, then “all places whose latitude equals the angle between the location of the Sun and the equator will experience Zero Shadow Days.”
Odisha: People witnessed Zero Shadow Day, a celestial phenomenon, in Bhubaneswar yesterday"It occurs twice a year when sun is directly overhead. We experienced it today. Can be experienced in Cuttack tomorrow," said Subhendu Patnaik, Deputy Director, Pathani Samanta Planetarium pic.twitter.com/7YugRo8H2Y
— ANI (@ANI) May 22, 2021
Patnaik said that Zero Shadow Day can be seen using white paper by placing it on flat ground, keeping some vertical object like a bottle on it and studying the movement of its shadow.
According to astronomy experts, during sun’s north to south and south to north movement, its’s declination and the latitude of a place within the tropics align briefly for two days in a year, during which shadows disappear momentarily.
In between these two days, the places between the Tropic of Cancer and Tropic of Capricorn witness zero shadow days on specific days. In Odisha, this year, people can experience the Zero Shadow Days starting from May 21 to June 2, depending upon their districts.