Why Transit of Venus is so rare?
Transit of venus is a very rare event which will be taking place on 5th and 6th june 2012. This event will repeat itself in the year 2117. It was last occured in 2004, and before that it took place in the year 1882. Venus transit always occurs in pair these are shown below
- 1631 and 1639
- 1761 and 1769
- 1874 and 1882
- 2004 and 2012
we can see a odd pattern here, it takes about 122.5 years for Venus to transit, and after one transit it repeats itself after 8 years. Now the next transit will occur in 105.5 years ,followed by another transit after 8 years (122.5 , 8 , 105.5 , 8).
If both Venus and Earth were in the same plane orbiting the sun, this transit would be happening frequently , but that is not the case here the orbit of Venus is inclined so it passes between sun and earth in every 1.6 years.
Its the same case with our moon. every month moon passes between sun and earth yet, we don’t see solar eclipse every month. This is because the orbit of moon is inclined slightly. Thus the new moon is usually little below the sun or little above the sun.
This will be the last time Venus will transit the sun in this century!! .