World Watches As Venus Passes Across The Sun

Skywatchers have gazed in awe as Venus passed in front of the Sun - an event that won't be seen again for another 105 years.

The transit of Venus began shortly after 10pm GMT on Tuesday in cloud-free areas of North America, Central America and the northern part of South America.

It was visible, with magnification, as a tiny black dot on the solar surface.

In Britain, Venus passed the sun in the early hours of Wednesday morning - at 5.37am in London - but the dreary weather blocked many views.

While the rain held off in places, there was cloud cover across much of the country .

In America, thousands of people flocked to universities and observatories to watch the spectacle using Sun-safe telescopes and on large screens.

Grey skies did not deter some 600 people from gathering for a watch party at Nasa's Goddard Space Flight Centre in suburban Maryland.

The US space agency had promised "the best possible views of the event" through high-resolution images taken from its Solar Dynamics Observatory (SDO) , in orbit around the Earth.

"A transit is a wonderful and rare sight; when you consider the vastness of the sky, for a planet to pass the disc of the sun is pretty unusual - and you do have to wait until 2117 for the next one," said the SDO's Richard Harrison.

The nearly seven-hour passage of the planet between the Earth and the Sun should only be viewed through approved solar filters to avoid the risk of blindness, experts warned.

Sunglasses were not strong enough to shield the eyes for viewing the transit.

All of the transit was visible in East Asia and the Western Pacific. Europe, the Middle East and South Asia got to see the end stages of the eclipse as the sun rose.

Scientists say that studying the transit will boost future efforts to identify distant planets and learn more about their atmospheres.

Only six transits have ever been observed (in 1639, 1761, 1769, 1874, 1882 and 2004) because the transit is invisible without magnification, though the event has happened 53 times between 2000 BC and 2004.

The next will not take place until 2117.