Bengaluru witnessed a unique celestial event on Friday as the city experienced 'Zero Shadow Day', a phenomenon where vertical objects cast no shadows for approximately one minute. This occurs when the sun is exactly at its zenith, directly overhead, causing the shadows to disappear.
What is Zero Shadow Day?
Zero Shadow Day is an astronomical event that happens twice a year for locations between the Tropic of Cancer and the Tropic of Capricorn. During this event, the sun's rays fall vertically on the Earth's surface at local solar noon, eliminating shadows of vertical objects. The phenomenon lasted for about a minute in Bengaluru, captivating residents and astronomy enthusiasts.
Why Does It Happen?
The event is a result of the Earth's axial tilt and its orbit around the sun. As the sun's declination matches the latitude of a place, it appears directly overhead at noon. For Bengaluru, located at 12.97°N, this alignment occurs on specific dates each year.
Astronomers and science educators often use this day to demonstrate the concept of the sun's apparent motion. Schools and planetariums in the city organized special viewing sessions to help students understand the phenomenon.
Residents were advised to observe the event safely by looking at the shadows of vertical poles or buildings. Many took to social media to share their experiences and photographs of the shadowless moment.
The next Zero Shadow Day for Bengaluru will occur later in the year, offering another opportunity to witness this rare natural occurrence. Such events highlight the dynamic relationship between the Earth and the sun, reminding us of the precision of celestial mechanics.
