'Zero Shadow day' in Udupi And Mangalore

An astronomical phenomenon , 'Zero  shadow day ' will be observed in Mangalore on April 24, August 18  and in Udupi on April 25,August 17.
According to press release from Dr. A.P Bhat ,Coordinator of Poorna Prajna Amateur Astronomers Club (PAAC), this phenomenon will commence and people will see their shadow disappear for a moment at noon.
This event occurs for a few moments

• at 12:28 pm on April 24 in Mangalore region 
• at 12:29 pm on April 25 in Udupi region 
  
  
• And people of Bangalore will observe this At 12:17pm

This Event occurs again on 

• at 12:34pm on August 17 in Udupi region 
• at 12:33pm on August 18 in Mangalore region 

What is 'Zero Shadow Day' ?

Zero shadow day is a day on which Sun does not cast shadow of an object at noon, when sun will be exactly at Zenith*

(*zenith- The point in the sky directly above an observer at any given location.Lie down on your back and imagine the sky is a giant dome.the highest point of the sky is called zenith)

Characteristics :

• Happens when Sun's declination becomes equal to the latitude of the place.
• happens Twice in a year.
• happens for the +23.5 degrees & -23.5 degrees of latitudes.
• the dates will be different for different places on Earth.
• zero shadow day are the days when the sun will raise at true east and set at true west.
• on every location of the planet between tropic of cancer and tropic of Capricorn , the zero shadow day is witnessed twice in a year.

• At 12:28 pm ,April 24& at 12:33 pm,August 18 in Mangalore Region (12°54'50.76'' N , 74°51'21.6''E)  Sun’s declination is +12°54' Latitude , +74°54' Longitude
• At 12:29pm , April 25 & at 12:34pm , August 17 in Udupi region (13°20'27.24'' N , 74°44'31.56"E), Sun’s declination is +13°18' Latitude ,74°42" Longitude 

here we can see that sun's declination is nearly equal to the latitude and longitudes of that place which causes zero shadow at that time.

Reason :

• In this event , the Sun shines exactly above the heads on these days .(In astronomy this point is called Zenith).So it is clear that , On zero shadow day , the sun passes through the Zenith as the result of which all the objects will have minimal or no shadow at that time.
• Because of the Earth's Tilt angle of 23.5 degrees , the Sun rises every day in the East ,gradually moving towards North till June 21st and then slowly proceeding towards the south till December 21st.As earth moves around the Sun and Revolves on its own axis ,For all the people between Tropic of cancer and tropic of Capricorn ,The sun at noon moves closer to zenith and passing through Zenith twice Causing two Zero shadow days per year.

                                                       -PVGANIGA

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