See Venus transit now, else in 2117

TIMES NEWS NETWORK 

Bangalore: Keep yourself free on June 6. For, a rare celestial event called the transit of Venus will take place, and it won’t happen again in your lifetime. The next transit of the Venus will take place only in 2117. 
    The Jawaharlal Nehru planetarium has introduced a new programme, ‘Transit of Venus — A small eclipse’, to capture this event when Venus will become visible. It is a smaller version of the eclipse, when, instead of the Moon, Venus will pass in front of the Sun. The event is rare as Venus will next become visible in 2117. 
    The programme, which was demonstrated on Tuesday, begins with an introduction to the night sky in spring and explains the distribution of constellations. The Moon will serve as a reference for identification of these groups of stars. The Moon and the change in its position day by day can be monitored to recognize the constellations in the sky. The names given to these groups long ago serve a very important purpose of specifying the directions in the sky. Many nebulae and star clusters can be recognized with the names associated with them. The movement of planets through the constellations is the only clue we have to understand the motion of planets in the solar system. The finer details like the inclinations in the orbital plane are needed to understand the phenomena like transits. The appearance of Venus like a dot as seen from the distance of Earth is presented with an imaginary journey from planet Venus to Earth. Venus transits are separated by about 120 years. The programme explains how we can see a pair separated by eight years. 
    The historical observations of the transit of Venus and their importance in the determination of the astronomical unit are covered in the programme with appropriate animations and graphics. The observations made from India in the 19th century are also narrated. 
TIME SPAN Transit of Venus happens only four times every 243 years 
However, spacing between each occurrence is very uneven 
It's 121½ years, then 8 years, then 105½ years, then 8 years again 
The last transit occurred in June 2004 - and after this year's June's event there won't be another until December 2117