The dark, narrow disc, known as the umbra, then races across the roof of the world before alighting in northern Siberia, where it will skip across central Russia and central Asia and head into Mongolia and northwestern China.
It then curves to the southeast before expiring near the city of Xian at 1120 GMT, after a trek of some 10,200 kilometres (6,375 miles).
Most of Asia, northern Europe and northern Canada will see a partial eclipse, weather permitting, according to Nasa’s veteran eclipse expert, Fred Espenak (http://eclipse.gsfc.nasa.gov/OH/OH2008.html).
“More than a billion people will be in the shadow of the Moon on August 1st,” says the US publication Sky & Telescope, which is backing a trip aboard a Russian icebreaker by US amateur astronomers, who will view the eclipse from the Arctic Ocean.Eclipses of the Sun – the bringer of light, and thus life – have long held a tenacious grip on the human mind.
To the ancient Chinese, the eclipse was a sun-eating dragon which had to be chased away with clashing cymbals and pans. For Vikings, two chasing wolves, Skoll and Hati, were to blame. In Hindu mythology, a spiteful demon called Rahu takes a bite out of the Sun from time to time.
The first known record of an eclipse was made in the reign of Zhong Kang, the fourth emperor of China’s Xia dynasty.
Because we know that several solar eclipses took place around that time, astronomers are uncertain of the exact date when this event took place – it could be 2128 or 2134 BC.But even then, the brief text shows that the eclipse was clearly mind-blasting.
Key facts
• Total solar eclipses occur when the Moon comes between the Earth and the Sun, completely obscuring the solar disk for a few minutes along a narrow path.
The eclipse follows a west-to-east track that can last several hours until this perfect alignment ends.
• The width of the path of the eclipse at totality is at most 269kms. The record duration of a totality is seven and a half minutes.
• The totality path is caused by the dark, cone-shaped umbra (the Latin word for “shadow”) of the Moon. On either side of the umbra is the penumbra (“almost shadow”), which is around 8,000 kilometres wide. In the penumbra, people see a partial eclipse.
• Total eclipses happen about once every 18 months, but there are also periods of relative infrequency. Partial eclipses are much more frequent, and may occur several times a year.
• Most eclipses occur at sea or in sparsely populated areas. The great total eclipse of Aug 11, 1999, was exceptional because it traversed such a populous area, from western Europe to India. The July 22, 2009, eclipse could be the most-viewed in human history, visible in a swathe from central India to central China.
http://www.dawn.com/2008/07/30/top13.htm
