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VENUS TRANSIT PICTURE COLLECTION | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| There are very rare periodic
astronomical events. One of these is the transit of Venus on June 8,
2004. On this day half our globe will be able to watch the tiny black dot
of the planet Venus moving across the disc of the sun. The previous
transit of Venus occurred on December 6, 1882 - one of merely five
events of its kind ever watched by humans. Venus Transit is the celestial phenomenon of the transit of the dark disc of the planet Venus in front of the shining disc of the Sun. It is, in fact, a partial eclipse of the Sun, very partial since the planet Venus will occult only a very small part of the solar disc, but which will be very easily observable for an informed public of the phenomenon. Why such a phenomenon is so rare? The planet Venus orbits around the Sun in 225 days between the Earth and the Sun. We should thus see this phenomenon at each revolution, i.e. each conjunction between Venus and the Sun, every 584 days. It would be true if Venus and the Earth were orbiting around the Sun in the same plane. The orbital plane of Venus being tilted of 3 degrees approximately on the orbital plane of the Earth, the planet Venus will pass generally above or below the solar disc and we will not see a transit. The figure below shows the phenomenon. |
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| For a Venus Transit to occur
it is necessary that the Sun, Venus and the Earth are aligned on the
intersecting line of the two orbital planes (called line of the nodes).
The Earth crosses this line in June and in December but Venus is simultaneously
there only very seldom, approximately twice by century.
Dates of transits: |
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...Cook's achievement was exceptional;
the 'Endeavour' was no great ship built to sail the oceans, but a collier,
just 109 feet long. Cook, a Lieutenant at the time, is unlikely to
have been consulted on what type of ship he would have liked, but the
Whitby built boat, so similar to those he had made his name in, suited
him perfectly. The supposed purpose for the voyage was to observe the
Transit of Venus, simply for astronomical interest. But the real reason
was to sail westwards and above all south, to discover the secrets
of the South Pacific. Sailing in August 1768, Cook passed Cape Horn
in January of the following year. He then crossed the Pacific to New
Zealand and sailed down the east coast of Australia before finding
his way back to Cape Town and from there along the coast of Africa
and home to England in 1771... |
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