Bhubaneswar: Smart City Bhubaneswar on Sunday experienced a ‘Zero Shadow Day’, when vertical objects appear to cast no shadow.
Zero Shadow Day (ZSD) is a rare celestial event that occurs when the Sun reaches its highest point in the sky. At this moment, the vertical objects will cast no shadows on the ground.
A large number of people including children throng to the Pathani Samanta Planetarium to witness the rare event, which was witnessed at 11:43 a.m. on Sunday.
“Today, the Sun reached exactly overhead at (11:43 a.m.) in Bhubaneswar and the shadow of any vertical object disappeared at that instant. Zero Shadow Day occurs twice a year in a particular place, said Subhendu Patnaik, Deputy Director, Pathani Samanta Planetarium.
The phenomenon was observed for 2 to 3 minutes in the city today. Cuttack city will witness the Zero Shadow Day on May 22 at 11.30 a.m., he said.
Uttarayan (movement of the Sun from south to north from winter solstice to summer solstice) and Dakshinayan (back from north to south) happen because Earth’s rotation axis is tilted at an angle of roughly 23.5° to the axis of revolution around the Sun.
Shri Patnaik explained that the Sun’s location moves from 23.5°N to 23.5°S of Earth’s equator and back. All places whose latitude equals the angle between the Sun’s location and the equator on that day experience zero shadow day, with the shadow beneath an object at local noon.
“For the first time, I have experienced this wonderful event. It enhanced my practical knowledge about how the Sun moves around the earth,” said a student, who was present at the planetarium.