Pune Witnesses Zero Shadow Day Virtually In Lockdown

Pune: May 13, 2021: Well, we all know wherever we go, our shadow follows us. But nature as always is exciting and the science has helped us to know that even our shadow can be invisible on specific days of the year. Today Pune witnessed zero shadow day at 12.31 pm.

Due to lockdown there was no live demonstrations today. Jyotirvidya Parisanstha (JVP), Pune-based astronomy group hosted a livestream of the event from their Kesariwada observatory on their social media channels on Thursday.

Let’s understand it

If sun comes exactly overhead, then the shadow can disappear. Every day at noon (12) the Sun comes overhead. But is it really true? The answer is No. Due to tilt of the Earth’s axis, sun travels 23.5° north and south of the celestial equator.

Hence when sun is crossing the celestial equator, then at the place on the equator of Earth, Sun rises exactly at the east point and crosses zenith (point exactly overhead) at 12 O’clock of local time. Then while travelling to north, when the Sun is at the celestial angle from equator same as that of latitude of our town, on that day, sun will be at zenith at 12 O’clock of local time, and the same day is known as Zero Shadow Day for a place. Obviously, this event never happens in the region above tropic of cancer and below tropic of Capricorn.

Zero shadow day will take place again in the month of July when the Sun is on its southward journey; but as it will be rainy season in India, we may not be able to observe this due to monsoon clouds.