NOVEMBER 29Amateur and professional astronomers from around the world are heading south of the equator, congregating in parts of southern Africa and southern Australia to view a total eclipse of the Sun that will take place on Wednesday, Dec. 4.
The path of totality, from where the disc of the Moon will appear to completely obscure the Sun, will average 35 miles (56 kilometers) in width and will race about 7,500 miles (12,000 kilometers) across Earths surface.
The total eclipse begins over the open waters of the South Atlantic Ocean, roughly 600 miles (966 kilometers) offshore of Angola. From this spot, at 5:50 Universal Time (UT), the rising Sun will become totally eclipsed for 26 seconds. The Moons dark umbral shadow will rapidly sweep in a southeasterly direction, reaching the Atlantic coastline of Angola just seven minutes later.
Continuing on a southeast trajectory across portions of southern and eastern Angola, the shadow will also touch parts of Zambia, Namibia, Botswana, South Africa and Mozambique. The umbra will take just over a half-hour to sweep over these six African nations; people at the center of the eclipse track will experience anywhere from 49 to 92 seconds of total eclipse.
The Moons umbral shadow will then sweep out over the Indian Ocean, where the duration of total eclipse reaches its maximum of 2 minutes 4 seconds at a point roughly 1,200 miles (2,000 kilometers) southeast of Madagascar.
Next stop: Australia
For the next hour and a half the shadow traverses open ocean waters, curving gently east, then northeast, finally making landfall again just before local sunset over sparsely populated South Australia, New South Wales and Queensland. The coastal town of Ceduna, in South Australia, stands to witness an especially spectacular sunset eclipse as the narrow track prepares to leave the Earths surface. Totality here will last just 33 seconds.
The shadow will take less than two minutes to sweep across 560 miles (900 kilometers) of the Australian Outback and will leave the surface of the Earth at 9:12 UT just to the northeast of the town of Old Tickalara. Those heading to the Australian part of the eclipse track will see the Sun in total eclipse for anywhere from 22 to 33 seconds.
For seasoned eclipse travelers, it would at first seem logical to set up in Africa where totality will last up to three times longer than in Australia. However, December marks the rainy season in southern Africa, whereas much drier and clearer weather is to be expected in Australia. Of course, Australias view of the total eclipse will be very short and since it occurs so close to sunset, there will be a better chance of local horizon clouds obscuring the Sun at the critical moment!
Interestingly, a specific geographic location plays host to a total solar eclipse just once every 375 years, on average. But the west coast of the African country of Angola is well ahead of those odds.
For a 40-mile stretch of its Atlantic coast, between the towns of Lobito and Sumbe, this will be the second total eclipse visible in less than 18 months; the last such case occurring on June 21st, 2001.
"The local residents there are indeed fortunate to witness two total eclipses of the Sun within the span of eighteen months," says NASA astronomer and eclipse chaser Fred Espenak.
Safety
There are a number of safe methods that one can follow to view the partial phases of the eclipse.
This will be the first total solar eclipse visible from any part of Australia since October 23rd, 1976. In contrast to this upcoming event where the totality path passes over a sparsely populated region, the track of the 1976 eclipse passed very close to Australias most populous cities such as Perth, Adelaide, and Sydney. While it is rather unusual for the track of a total solar eclipse to cross a large metropolitan area, Melbourne, Australias second largest city, found itself directly in the totality path of the 1976 eclipse.
Yet, back then, local authorities that were deeply concerned that people would suffer permanent eye damage tempered this very fortuitous circumstance considerably. The Melbourne Sun, for instance, published daily warnings in nine foreign languages. In the days leading up to the eclipse, newspapers and broadcasts everywhere emphasized an "Eyes Down on E-Day!" campaign, urging all residents not to look at the eclipse at all and suggesting that children especially should be kept indoors.
Such methodology can prove to be a double edge sword.
True, failure to use proper observing methods may result in permanent eye damage. Studies have shown that most individuals who sustain eclipse-related eye injuries are children and young adults.
On the other hand, it is those precious moments of totality, when the Moon has completely covered the Sun that are perfectly safe to look at. Those who have witnessed the stark beauty firsthand describe a total eclipse of the Sun as the most awe-inspiring event Nature can offer. Yet, many who have been fortunate to live within the narrow zone of past total eclipses have completely missed out on this awesome spectacle because they have been scared into not looking at the eclipse at all.
"This tactic may backfire, particularly when the messages are intended for students," says solar eclipse expert Jay M. Pasachoff of Williams College in Williamstown, Massachusetts. "A student who heeds warnings from teachers and other authorities not to view the eclipse because of the danger to vision, and learns that other students did see it safely, may feel cheated out of the experience. Misinformation may be just as bad, if not worse than no information." (Pasachoff also serves as the U.S. National Representative to the Commission on the teaching of astronomy of the International Astronomical Union.)
Looking ahead: On May 31, 2003, there will be an annular eclipse of the Sun, in which the Moon blots out all but a ring of the Sun, visible from parts of Greenland and Scotland, as well as all of Iceland. The next total solar eclipse is scheduled less than a year from now, on November 23, 2003. Antarctica anyone?
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 Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for The New York Times and other publications, and he is also an on-camera meteorologist for News 12 Westchester, New York. |
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