Aug. 1999
International Audience for Huge Eclipse Show
By HENRY FOUNTAIN
The solar eclipse that will sweep across Europe, the Middle East and the Indian subcontinent on Wednesday promises to be one of the most watched in history. The European portion of the itinerary alone reads like one of those if-it's-Tuesday-it-must-be-Belgium tours: Cornwall, Paris, Stuttgart, Munich, Vienna, Budapest and Bucharest are all within or near the 60-mile-wide path of totality, where the moon will completely cover the sun.
Even people in the northeastern United States will have a chance to see a partial eclipse at sunrise, weather permitting. In New York, about one-third of the sun will be obscured when it rises at 6:02 A.M., with coverage diminishing to zero in a half-hour. Farther north and east, the situation improves. In Boston, for example, the sun will be about two-thirds covered when it rises at 5:47.
Experts caution that even a partial eclipse can harm the eyes. It should be viewed through a special solar filter (sunglasses or photographic filters are inadequate) or by projecting the image through a pencil-size hole in a piece of cardboard onto a sheet of paper.
The eclipse comes near what is known as solar maximum, the end of an 11-year cycle when flares and other events increase. So the corona, the sun's outer atmosphere that is only visible during a total eclipse, may be particularly spectacular.
But astronomers also hope to learn more about why the corona is so hot -- millions of degrees, when the sun's surface is a mere 6,000. Data from research spacecraft have suggested that magnetic fields near the surface may play a role.
A team from Williams College is in Ramnicu-Valcea, Romania, where the duration of totality will be the longest at just under two and a half minutes, to try to observe rapid oscillations in the corona that would be evidence of magnetic fluctuations. The team, led by Jay Pasachoff, the head of the school's astronomy department, is working in conjunction with one of the orbiting observatories, the Transition Region and Coronal Explorer. But that spacecraft can take only one photograph every 10 seconds or so; because the oscillations would be on the order of one every second, the ability of the ground-based crew to make a rapid series of images is critical.
"It's a perfect example of how eclipse results can overlap and collaborate with space results," Dr. Pasachoff said.