Bengaluru to witness the Zero Shadow Day on August 18, 2nd astronomical miracle of 2023

For the second time in 2023, on August 18, Bengaluru is preparing to observe the heavenly astronomical phenomena known as Zero Shadow Day. The city will experience a brief celestial event at 12:24 pm when the Sun will be directly overhead. This timing was determined by astronomer Alok Mandavgane. Vertical things like poles, sticks, and even people will not throw any shadows on the ground at this period. You won't be able to see your shadow until the sun reaches its zenith unless you jump.

According to science, locations between the Tropics of Cancer and Capricorn, or latitudes of 23.5 and -23.5 degrees, experience Zero Shadow Day twice a year. On April 18 of this year, Bengaluru had Zero Shadow Day; notably, around 12.17 pm, vertical objects lost their shadows for a brief period. The same phenomena was seen in Hyderabad on May 9 and again on August 3 at 12:23 p.m.

Let's examine the underlying fundamental scientific theory that explains this amazing celestial phenomenon in order to comprehend the mystical event.

Science behind the phenomenon

According to the Astronomical Society of India, "the Sun is almost never exactly overhead at noon, but usually transits a bit lower in altitude, a bit to the north or a bit to the south." According to science, "the Earth's rotation axis is inclined at 23.5 degrees to the plane of its revolution around the Sun, which is why we have seasons." Additionally, according to the ASI website, "this also indicates that the Sun will shift from 23.5 degrees south of the celestial equator to 23.5 degrees north of the equator (Uttarayan) and back again (Dakshinayan) in a year when it is at its greatest point of the day.

In the Uttarayan and the Dakshinayan, the Sun's declination will be equal to the latitude of those who live between +23.5 and -23.5 degrees latitude twice. The Sun will be directly overhead at noon on these two days, and no object will throw a shadow on the earth.

Understanding the Zero Shadow Day (ZSD) theory

Over the course of a year, there are variations in the sun's passage across the sky. Visualize a gigantic dome-shaped structure in the sky. The summit of this celestial dome is the zenith. The moment the light reaches this point, your shadow exactly aligns beneath you. This only occurs twice a year, and both occasions are on Zero Shadow Days.

When does ZSD happen?

The exact time of solar noon at a particular location must be met in order for the Zero Shadow Day event to occur. Every location experiences this phenomenon at a different time and date. While solar noon has been observed at 12 o'clock in the afternoon, its exact time varies depending on the location and the season because of the Earth's tilt and orbit around the Sun.

When it will happen on August 18 in Bengaluru

On August 18, 2023, the Sun will pass directly above in Bengaluru at 12:24 p.m. Any vertical object's shadow would vanish at that same instant.

How to witness Zero Shadow Day

You'll notice your shadow gradually vanishing as the projected moment of solar noon approaches. Nearby objects, such poles, won't have any shadows and appear to be hovering in midair. On your rooftop or the ground, you can place items such as water bottles, torches, bottles, rods, pipes, and more in the sunshine and observe how their shadow lengths change as the day goes on. Eventually, the shadow will entirely disappear for a brief period of time about 12:24 pm. This moment marks the Zero Shadow time.