Venus, the planet which could be observed on June 8th, 2004.This event can be observed once in decades. Venus transit in front of the Sun itself lasts more than two hours. The diameter is about 1/30 the Sun diameter.
During the history there have been a few Venus transits observed - in 1631, 1639, 1761, 1769, 1874, and 1882. The first person to predict the transit was Johannes Kepler.
That occurred in 1631 but nobody could se it because of the bad weather in Paris. The second transit was expected by Jeremy Horrocks, who was probably the first person
to see the event in 1639. Later on many astronomers kept on taking often very dramatic expeditions to the distant places. The reason was simple- to trace and elicit the
distance of the Earth from the Sun through derivation from the moments of the beginning and the end of the event at different places on the Earth. It was not easy at all ,
as these moments was difficult to measure exactly. That was because of the teary shape of the picture of Venus. This effect is the same with every Venus transit including
that of this year.
Next Venus transit will happen in 8 years - on June 6th, 2012 , but only the end of the event will be possible to observe at the area of the Czech Republic.
The next transit will be after 105,5 years - on December 11th, 2117.