BHUBANESWAR: Have you ever observed your shadow vanishing under Sun? If not, then wait for the rare and interesting terrestrial event next week when your shadow will be exactly under you.
There will be no shadow of any object when the Sun is at its zenith around noon. The Zero Shadow Day (ZSD) can be observed in all parts of the State on different dates and times.
While the residents of Bhubaneswar can observe it at 11.43 am on May 21 and 11.53 am on July 22, it can be seen at Cuttack around the same time on May 22 and July 22.Enthusiasts can witness it at 11.52 am on May 28 and 11.56 am on July 15 in Burla, 11.54 am on May 23 and 12.04 pm on July 20 in Balangir, 11.41 am on May 31 and 11.49 am on July 12 in Baripada and 11.58 am on June 2 and 11.56 am on July 10 in Rourkela.
Deputy Director of Pathani Samanta Planetarium Subhendu Pattnaik said the ZSD fall during the Uttarayan when the Sun moves northwards and Dakshinayan when the Sun moves southwards.
“The event can be observed between Kanyakumari and central India below the line of Tropic of Cancer which passes through eight States - Odisha, Rajasthan, Gujarat, Madhya Pradesh, Chhattisgarh, Jharkhand, West Bengal and Tripura,” he informed.
There are two ZSDs every year for every point on Earth between the Tropics of Cancer and Capricorn.
The Tropic of Capricorn passes well below the Indian land mass whereas the Tropic of Cancer passes through central India little above Odisha.It happens because Earth’s rotation axis is tilted at an angle of 23.5° to the axis of revolution around the Sun. The Sun’s location moves from 23.5° N to 23.5° S of Earth’s equator. All places whose latitude equals the angle between the Sun’s location and the equator will experience ZSDs.
Meanwhile, scientists in association with various organisations like Astronomical Society of India and planetariums have urged students and enthusiasts to observe the event as a fun and learn the science behind it.Pattnaik said various activities like jumping in the air to see one’s own shadow and lodging a stick vertically into level ground to see how its shadows play around are being organised to help school students learn simple concepts on the motions of the Earth.
“People can witness the event at the planetariums in Bhubaneswar and Burla. One can also observe it before noon by placing any symmetrical object like bucket, pole, cardboard box and bottle vertically on a plane surface under the direct sun. The length of shadow will go on decreasing and will disappear for some time,” he added.