Odisha’s Bhubaneswar witnessed a rare celestial phenomenon called Zero Shadow Day on Friday.
During the occurrence, no shadow of an object or a being is observed. Bhubaneswar witnessed this rare event at 11:43 am and it continued for a brief period of about three minutes.
The phenomenon occurs twice a year when the sun is at its highest point in the sky at all the regions between the Tropic of Cancer and the Tropic of Capricorn. Due to the sun being exactly overhead, the shadow of all beings or objects disappears, resulting in Zero Shadow Day.
To witness this special phenomenon one can use a white paper and place it on a flat ground and keep some vertical object like a bottle on it and study the movement of its shadow,
The phenomenon takes place as the rotation axis of the Earth is tilted at an angle of 23.5° to the axis of revolution around the Sun. When the location of the Sun moves from 23.5° N to 23.5° S of Earth’s equator, all places whose latitude equals the angle between the location of the Sun and the equator will experience Zero Shadow Days.
During the sun’s apparent North to South and South to North movement, there are two days in a calendar year when the sun’s declination and the latitude of a place within the tropics align briefly, making shadows disappear for a short while.
In Odisha, different districts can experience the Zero Shadow Days starting from May 21 to June 2.