Millions of people in Europe and South Asia are expected to stop work and look to the heavens today to catch a glimpse of the last total solar eclipse of the millennium. Heavy cloud conditions predicted last night by meteorologists appeared to have done little to darken the enthusiasm of those hoping to see the eclipse. Across Europe, thousands of businesses have made arrangements for workers to down tools this morning (GMT) so they can watch the moon's shadow race across the Earth's surface. In London, the Chamber of Commerce estimates that the event will cost Britain GBP500 million (HK$6 billion) in lost trade. Although a total eclipse of the sun - when the moon completely obscures the sun - can be witnessed somewhere on Earth every 18 months or so, it is rare for one to pass across such densely populated areas. 'Probably the biggest thing about this eclipse is that it is passing one of the highest populated centres in the world - central Europe - so it gives a lot of people an opportunity to see a major eclipse,' said Fred Espenak, eclipse specialist at America's National Aeronautics and Space Administration. The eclipse will begin in the North Atlantic, about 300km south of Nova Scotia, hit Cornwall in south-west England half an hour later, then sweep across central Europe and the Middle East before ending at India's Bay of Bengal less than three hours later. The end of the eclipse's track is likely to be hidden by cloud due to India's rainy season but thousands of people are expected to gather at holy sites across the subcontinent to celebrate the event at temples dedicated to the sun and stars. Scientists hope to take advantage of the eclipse to conduct thousands of experiments and observations in disciplines ranging from astronomy to marine biology. When the sky turns black in Britain, one group of experts hope the eclipse will throw new light on the eating habits of cows. In an attempt to prove cattle do not like eating in the dark, the scientists will monitor the behaviour of a specially selected herd which has been wired up with computers attached to collars.