What is Zero Shadow Day? All you need to know

What is Zero Shadow Day? 

Zero Shadow Day is a phenomenon that occurs twice a year in locations between the Tropics of Cancer and Capricorn, where the Sun reaches its highest point in the sky. On these days, the Sun is directly overhead at local solar noon, causing an object to cast no shadow. Today, Bengaluru will observe this phenomenon at 12:17 pm. Let’s know the reason behind the occurrence of Zero Shadow Day. 

Zero Shadow Day 2023: Date, Time, and Place

Where does Zero Shadow Day occur?  

 As per the Astronomical Society of India, Zero Shadow Day occurs in regions near the equator between the Tropic of Capricorn and the Tropic of Cancer. This phenomenon occurs twice a year when the angle of the sun is such that it is almost directly overhead.

The dates of Zero Shadow Day vary depending on the latitude and longitude of a particular location. According to the Indian Institute of Astrophysics, the next shadow day in Bengaluru will be on the 18th of August. 

Why does Zero Shadow Day occur?  

The occurrence of Zero Shadow Day is explained due to the tilted axis of the Earth and its orbit around the sun. As the Earth orbits the sun, the angle at which the sun's rays hit the Earth's surface changes, causing shadows to be cast in different directions. 

At the equator, the sun's rays are almost perpendicular to the Earth's surface on two days of the year, causing Zero Shadow Day to occur. In other parts of the world, the angle at which the sun's rays hit the Earth's surface is not as perpendicular, so Zero Shadow Day does not occur.