Bengaluru gears up for second Zero Shadow Day in 2023. What you need to know

Do you recall the surreal experience when residents of Bengaluru walked in the sunlight devoid of their shadows beside them?

Well, that extraordinary phenomenon, famously known as Zero Shadow Day, has made its return. The city, often likened to the Silicon Valley of India due to its vibrant IT sector, is gearing up to celebrate this unique occurrence once again today.

This remarkable celestial event, which initially graced us on April 25, 2023, is making its comeback on August 18 of the same year.

What is Zero Shadow Day?

• Zero Shadow Day, also referred to as No Shadow Day, is a distinctive event that transpires in select parts of the world.
• During this phenomenon, the Sun is positioned directly overhead at a specific moment, causing objects to cast minimal to no shadows.
• This phenomenon arises due to the Earth's axial tilt and its orbital motion around the Sun.

• Imagine a line encircling the Earth's midpoint, termed as the Equator.
• Above and below the Equator, there exist two lines known as the Tropics.
• Within this zone, instances occur when the Sun is precisely positioned at the zenith around noon.
• This unique occurrence results in objects such as poles or sticks appearing to possess very short or no shadows, as sunlight directly descends.

Why does this occur?

• This extraordinary phenomenon stems from the Earth's tilt, which directs the Sun's rays to strike the Earth more perpendicularly in specific regions during certain periods of the year.
• Bengaluru, situated approximately 13 degrees North of the Equator, last witnessed this spectacle in April of this year.
• This event transpires twice annually for locations located between the Tropics of Cancer and Capricorn.

What to expect

• According to the Astronomical Society of India (ASI), when the sun is directly overhead, it eliminates shadows on objects.
• If you inhabit a region situated between +23.5 and -23.5 degrees latitude, something remarkable occurs twice a year: during the Northern Solstice and the Southern Solstice.
• Precisely at noon on these dates, the sun is positioned directly above your head, resulting in objects on the ground casting no shadows.

• To witness this phenomenon, it's crucial to be present at the precise moment around noon when the sun reaches its zenith.
• Selecting a location with an unobstructed view, such as open areas, is advisable.
• In urban settings like Bengaluru, being atop a rooftop can enhance your chances of observing the vanishing shadows.

Hyderabad also encountered Zero Shadow Day on August 3 at 12:23 pm when the sun was directly overhead, leading to a momentary disappearance of vertical object shadows. Furthermore, Hyderabad had previously witnessed this occurrence on May 9 in the same year.