Zero shadow Day in Bengaluru today: What is it, Why does it happen?

Mangalore Today News Network/News18

Bengaluru, April 24, 2024: Bangaloreans will experience a rare celestial phenomenon on Wednesday, April 24, which will make their shadows completely disappear. Known as Zero Shadow Day, the phenomenon will be experienced by places in the same latitude as Bengaluru in India and will occur between 12:17 PM and 12:23 PM across the city.

 

A Zero Shadow Day occurs twice a year at a time when the sun is positioned directly overhead, resulting in objects casting zero shadows at noon. Notably, the event is typically observed in regions near the equator when the sun’s angle is nearly perpendicular to the earth’s surface.

What is a Zero Shadow Day?

According to the Astronomical Society of India (ASI), Zero Shadow Day occurs twice a year for all the places between +23.5 and -23.5 degrees latitude. During this time, the sun is nearly overhead at noon but transits a bit lower in altitude, a bit to the north or a bit to the South, resulting in zero shadows on the Earth.

For people living in these two particular degrees of latitude, the sun’s declination will be equal to their latitude twice – once during Uttarayan and once during Dakshinayan. During these two days, the sun remains exactly overhead and will not cast a shadow of an object on the earth.

Important Facts About The Phenomenon
   
  1. Zero shadow day is closely linked to the Earth’s axial tilt.
   
  2. It happens twice a year in regions near the Tropic of Cancer and the Tropic of Capricorn.
   
  3. It happens in May and July or August.
   
  4. Zero Shadow Day helps scientists and astronomers study the movement and position of the sun and understand the earth’s tilt including its orbit around the Sun.
   
  5. The Indian cities of Chennai, Mumbai, and Pune are located between the Tropic of Cancer and Capricorn, thus having higher chances of having Zero Shadow Day

  6. The Zero Shadow Day usually lasts for a fraction of a second but the effects can be seen for a couple of minutes.

  7. The sun’s rays are not perfectly parallel even on a sunny day. However, the atmosphere bends the light rays to make them converge slightly.

In the meantime, the Indian Institute of Astrophysics (IIA) will organise special events on Zero Shadow Day at its Koramangala campus. The public has been invited to take part in the activities, where attendees will have the chance to observe the phenomenon.

Zero Shadow Day FAQs

What is Zero Shadow Day Phenomenon ?

Zero Shadow Day (ZSD) is a phenomenon that occurs twice a year in places located between the Tropic of Cancer and the Tropic of Capricorn. During this time, for a brief period, the sun is directly overhead, causing objects to cast no shadows.

Why does Zero Shadow Day happen?

Earth’s tilt on its axis and the sun’s apparent movement throughout the year cause this phenomenon. Twice a year, the sun reaches a point directly overhead at specific latitudes. When this happens, the sun’s rays hit the ground at a 90-degree angle, eliminating shadows for a short time.

Where can you observe Zero Shadow Day?

Only locations between the Tropic of Cancer (roughly 23.5 degrees north) and the Tropic of Capricorn (around 23.5 degrees south) can experience Zero Shadow Day.

When does Zero Shadow Day occur?

ZSD happens twice a year, around the times of the summer and winter solstices. The exact dates can vary slightly depending on the specific location.

How long does Zero Shadow Day last?

The period with no shadows is very brief, typically just a few minutes or even seconds. However, the effect might be noticeable for a slightly longer duration.

Is there any significance to Zero Shadow Day?

Beyond being a cool celestial event, Zero Shadow Day can be used to verify the sun’s position and calibrate astronomical instruments.

Are there any safety precautions for Zero Shadow Day?

Zero Shadow Day itself doesn’t pose any safety risks. However, looking directly at the sun can damage your eyes, so avoid doing so during this event or any other time.