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Dark side of the sun

John Parkinson is among those aiming to make the most of Britain's 1999 eclipse. "We want to get as many people as possible to understand what is going on and get involved with it," he says. From his own "back-of-the-envelope calculation", he reckons that some 40 million people in Britain will be in the zone where at least 90 per cent of the sun disappears. So he and a team of his students from Sheffield Hallam are working on ways to enable people, particularly schoolchildren, "to make observations of a once-in-a-lifetime event." They will take a number of experimental devices to Curacao in the Carribean this month "to test them in the field during a real eclipse" with additional help from pupils at an international school on the island.

The Sheffield Hallam team will include four undergraduates, three of whom are working for degrees in media science, a course that, in Parkinson's words, "teaches them the science relevant to everyday life and how you communicate it, which is exactly what this project is about."

What devices will they be trying out? "I don't want to give too many of the details away, but we're aiming to develop a projection system that will throw an image big enough to see on a wall, so that you can draw on it every couple of minutes and build up a record. We don't want to use binoculars and telescopes because not everybody's got them. We just want to use simple everyday bits and pieces - to get kids in schools to do almost a Blue Peter job of improvisation."

Viewing the sun directly, even during an eclipse, can damage the eyes , so his team's main aim is to arrive at "a safe method for watching the partial phases of the eclipse to develop and record their own eclipse - because different parts of the country will see different things." (The maximum period of total eclipse over Britain will be two minutes six seconds.) Parkinson's team will be joined on Curacao by Neil Tunstall, head of science at Helston School in Cornwall, which is very near the centre line of the 1999 eclipse's "path of totality", and his pupils. Tunstall will also be reporting back to Chris Davis at the Rutherford Appleton Laboratory on a "dry run" for a possible schools' experiment in 1999 on how the eclipse affects radio waves. Davis is studying how the sun's ultraviolet rays create and maintain the earth's ionosphere, which reflects radio waves. "It's not often you get to turn the sun off," he comments, "so the total eclipse is the nearest we can get to a controlled experiment." He is hoping to organise a "megalab" experiment in 1999 "to build up a map of radio propagation across the UK during the eclipse."

Of course, the 1999 eclipse will not just be visible in southwest England.The path of totality will also pass through Northern France, Luxembourg, southern Germany, Austria, Hungary, Romania, the Black Sea, Turkey, Iraq, Iran, Pakistan and central India, ending at sunset over the Bay of Bengal. Which means that an experienced eclipse watcher like Francisco Diego will not be making his observations in Cornwall next year. "It'll be too crowded. I'm looking for somewhere on the European mainland where good weather is more likely - and good roads too, so you can move somewhere better if the weather's no good."