Cosmic quirk explains Australia eclipse
PARIS - Aboriginal myths, tropical Australia, and the Great Barrier Reef provide a stunning backdrop next week to an eagerly-awaited total eclipse of the Sun.
For over three hours next Wednesday, the alignment of our Sun, our Moon and our planet will create one of the most spectacular sights in Nature.
The bringer of light and life is briefly blotted out, replaced by a corona of gold, its face obscured by a dark disc. Daytime stars appear in an indigo sky. The temperature eerily drops. Birds, confused by the strange coming of night, may fly into buildings and bats may leave their roosts.
A swathe of northern Australia, led by the tourist paradise of Queensland, is the only place where the eclipse will be viewed by many people, for the event will mainly take place over the vast, uninhabited South Pacific.
The light show starts at 2035 GMT Tuesday -- shortly after daybreak local time on Wednesday -- when the Moon's shadow, or umbra, falls in the Garig Gunak Barlu National Park in the Northern Territory, about 250 kilometers (155 miles) east of Darwin, according to NASA eclipse-meister Fred Espenak. (http://eclipse.gsfc.nasa.gov/OH/OH2012.html#SE2012Nov13T).
The umbra then flits eastward, across the Gulf of Carpentaria, before alighting in Queensland, where eclipse junkies -- some of them well-heeled Europeans and Americans on specially-organized trips --- will gather in Cairns and Port Douglas, the gateways to the Great Barrier Reef. Weather permitting, they will get two minutes of "totality."
After a 14,500-km (9,062-mile) trek, the three-body ballet comes to an end at 2348 GMT about 800 km (500 miles) west of Chile.
Outside the path of totality, a partial eclipse will be visible in Papua New Guinea, the extreme eastern part of Indonesia, the eastern half of Australia, the whole of New Zealand, Polynesia, part of Antarctica and the southern part of Chile and Argentina, says Britain's Royal Astronomical Society (RAS).
The legends of Australia's native peoples show eclipses to be of huge importance, says Duane Hamacher, an expert on Aboriginal astronomy at the University of New South Wales. The Moon is often seen as a man and a woman who chase each other across the sky, sometimes fighting, sometimes loving.
"In Euahlayi culture, the sun woman, Yhi, is constantly pursuing the moon man, Bahloo, who has rejected her advances," Humacher says in his blog (http://aboriginalastronomy.blogspot.com.au/2011/08/solar-eclipses-part-i.html).
"Sometimes Yhi eclipsed Bahloo, trying to kill him in a jealous rage. However, the spirits that held up the sky intervened and drove Yhi away from Bahloo.
The Yolngu people of Elcho Island in Arnhem Land provided a similar, but less malevolent, explanation for a solar eclipse -- it was an act of copulation between the sun woman and moon man."
As in other parts of the world, eclipses in Aboriginal communities were seen as a sign of impending calamity or black magic, a threat that could be addressed by medicine men, or wirreenuns, who chanted a particular set of words or threw sacred stones or a boomerang at the eclipsing Sun.
Mathematicians say total solar eclipses happen because of a remarkable celestial coincidence.
The Sun is 400 times wider than the Moon, but it is also 400 times farther away.
The symmetry means that when the Moon is exactly in line between the Sun and Earth, it completely obscures the solar face for people who are in its shadow, or umbra.
For those positioned outside a roughly 150-kilometer (95-mile) -wide central path but who are still partly in the Moon's shadow, the eclipse is partial -- it looks as if a bite has been taken out of the Sun.
Total eclipses are rare, and can be seen from a given point on Earth's surface only once every 410 years in the northern hemisphere, but only once every 540 years in the southern hemisphere.
The last total eclipse was on July 11, 2010, again over the South Pacific; the next will take place on March 20, 2015, occurring over Iceland, the Feroe Islands and Norway's far northern Svalbard archipelago, according to Espenak.