Kolkata to witness ‘Zero shadow moment’; Here's what is it? Why it happens?
Premium- On Zero Shadow Day, not just humans, but anything out in the sun did not cast any shadows at all.
West Bengal's capital Kolkata will have its zero shadow moment today, June 5 where there will be no shadow from sunlight at a particular time of the day. This rarest cosmic event happens twice a year when the sun is exactly overhead.
What are zero shadows?
According to astrophysicist Debiprosad Duari, "Any form of the visible light falling on an object generally produces a shadow, unless it is exactly above the object. People and any object, all around the world, living between the Tropic of Cancer and Tropic of Capricorn ( 23.5 and -23.5 degrees latitude) lose their shadows, though momentarily, twice a year. These two days are called zero shadow days".
Zero shadow day in Kolkata?
Kolkata is around 2,500 km from the equator and around 93.5 km from the Tropic of Cancer, the imaginary line which passes close to Krishnanagar in the Nadia district.
For Kolkata the first zero shadow day this year will be on June 5, 2022. And on July 7, there will be the second zero shadow day of the year.
Every year on the zero shadow days, students and astrophile who are located between the two Tropics erect vertical poles, and different objects and sometimes even stand outside to see for themselves the cosmic event.
Duari said this event also reminds the people of the motions and position of celestial bodies with respect to Earth which have direct links to events on the planet like the change of seasons, tides, and eclipses besides the zero shadow moments. The sun is rarely exactly overhead at noon, but usually transits a bit lower in altitude a bit to the north or a bit to the south.
Last month on May 14, Mumbaikars witnessed Zero Shadow Day in which not just humans, but anything out in the sun did not cast any shadows at all.