for National Geographic News
The total solar eclipse occurred on Tuesday, December 3, 2002.
Amateur and professional astronomers are flocking to the southern hemisphere to catch one of nature's greatest showsa total eclipse of the sun. The spectacle gives earthlings a rare glimpse of the corona, the scorching hot and faint outer atmosphere of the sun.
"Solar eclipses are spectacular to watch because of the drama of the sky going dark in the daytime, the blue sky going away, the rapid changes in the sun," said Jay Pasachoff, an astronomer from Williams College in Massachusetts.
Pasachoff and his team of colleagues and student astronomers on an eclipse expedition to study the corona will join throngs of spectators in the normally sleepy coastal town of Ceduna, Australia to catch the tail end of the eclipse, which occurs less than an hour before local sunset.
The spectators in Ceduna and sprawled out along the track of totality [see sidebar], which will average 35 miles (56 kilometers) in width, will come from far and near. Among those from afar is Oliver Staiger, a self-proclaimed eclipse chaser from Switzerland who is in Australia to witness his seventh total eclipse.
"I like to travel and have a challenge, a goal, when I travel," he said. "And once you've seen a total eclipse it is difficult to not hunt for the next one. You get addicted to it."
Staiger works as rental car agent and limousine chauffer in Geneva to fuel his eclipse habit. He also maintains a popular Web site on eclipses and leads eclipse trips for Astronomical Tours, a U.S.-based travel company.
Pasachoff, an avid eclipse-chaser himself, will witness his 35th solar eclipse as he conducts a series of experiments to study the solar corona with colleagues and students from Williams College.
"We are studying how the solar corona got to be 2 million degrees [Celsius], what its polarization is, and how features that form on the solar surface propagate into the corona and even out to the Earth," he said.
Observations of the corona are possible from Earth only during the brief moments of a total solar eclipse. The corona is usually hidden by the blue sky as it is about a million times fainter than the photosphere, the layer of the sun seen shining every day.
Solar eclipses are possible only because the sun and the moon appear to be about the same size in the sky. In reality, the sun is about 400 times bigger than the moon, but it is also about 400 times further from the Earth than the moon, according to astronomers.
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