Bengaluru To Witness 'Zero Shadow' Phenomenon On April 24: Know Details  

Zero Shadow Day occurs as Sun’s apparent path changes throughout the year it reaches a point where it is directly overhead at certain latitudes—leading to a moment when no shadow is formed.

All locations in India situated below the Tropic of Cancer—including Bengaluru, Chennai, and Mangaluru—experience Zero Shadow Day, Ramanujam told PTI.

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Bengaluru residents can witness an astronomical event known as Zero Shadow Day, on April 24 at precisely 12:17 PM, during which vertical objects will cast no visible shadow as the Sun aligns directly overhead. According to the Indian Institute of Astrophysics (IIA), this phenomenon occurs when the Sun reaches its zenith—positioned at a 90-degree angle to the ground—causing any shadow cast by upright objects to fall directly beneath them, effectively disappearing from view.

Dr Niruj Mohan Ramanujam, who heads IIA’s Science Communication and Outreach division, explained that this unique occurrence happens twice a year in locations situated between the Tropic of Cancer and the Tropic of Capricorn. For Bengaluru, Zero Shadow Days typically fall around April 24–25 and August 18.

All locations in India situated below the Tropic of Cancer—including Bengaluru, Chennai, and Mangaluru—experience Zero Shadow Day, Ramanujam told PTI.

What Makes Zero Shadow Day Special?

Zero Shadow Day is a result of the Earth’s axial tilt and its revolution around the Sun. As the Sun’s apparent path changes throughout the year, it reaches a point where it is directly overhead at certain latitudes—leading to a moment when no shadow is formed.

The phenomenon gradually moves northward and will reach its farthest point—the Tropic of Cancer—on June 21, coinciding with the summer solstice and marking the end of the Sun’s northward journey known as Uttarayana in the Hindu calendar, said Ramanujam.

Unlike an eclipse or meteor shower, Zero Shadow Day is a quiet yet intriguing event that requires nothing more than a vertical stick or pole to observe. At exactly solar noon, any upright object will cast a minimal or no shadow, which then lengthens again as the Sun continues on its path across the sky.

Cities like Chennai, Mangaluru, and other regions south of the Tropic of Cancer also experience this phenomenon twice annually, making it a recurring but lesser-known celestial event.