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- PARIS (AFP) - Two minutes.
That's all you have to make the most of what many astronomers regard as
the experience of a life-time. There's nothing like it. So be prepared.
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- Experts agree that a total solar eclipse, when the moon
passes directly in front of the sun, has few rivals as a sensory "high",
when the sights, sounds and feelings induced by the intricate cosmic dance
rise to a dizzying climax.
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- Advance knowledge of the sequence of events means you
need not be left struggling to keep up.
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- The initial, partial phase that precedes the total eclipse
is deceptively non-eventful, as the moon's disc inches its way across the
sun and the light dims very slowly in a build-up lasting more than an hour.
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- But then as totality approaches, and the sun is reduced
to a thin sliver, the special effects come into play.
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- The sun's rays, refracted by turbulence high in the atmosphere,
flicker on the ground, producing "shadow bands", patterns of
light and dark that shimmer like the shadows on the bottom of a swimming
pool produced by the ripples on the surface.
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- The air cools, a breeze may start blowing, and an eery
quiet falls, broken only by the call of birds confused and panic-stricken
at the unscheduled fall of night.
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- As the sun slips behind the moon, its light breaks through
the lunar valleys until the moon's black orb appears to be wearing a string
of pearls, the so-called Baily's beads.
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- These flick off one at a time, until light is left shining
at a single point on the lunar circumference in one of the most spectacular
phases of the eclipse, the "diamond ring".
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- The onset of totality is announced by the arrival from
the west of a huge, onrushing shadow, a wall of darkness that bears down
at more than 2,000 kilometres an hour. At this point the moon has covered
the solar disc entirely, and the sun-gazer can now safely remove the protective
glasses he or she has been wearing.
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- The black hole of the moon is now breathing fire: this
is the sun's corona, its superhot outer atmosphere which is normally invisible
but which now appears as a misty, white halo. Tongues of flame may project
to the east and west, with prominences -- loops of light -- as the sun
ejects streams of glowing gas.
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- Meanwhile the planets and other stars will have become
visible, and there will be innumerable distractions from other eclipse-watchers
as they gasp in wonderment and the bats come out and the automatic street
lights turn on, all adding to the sense of unreality.
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- Two minutes, and it is over. A brilliant light, the second
diamond ring, appears on the moon's rim, and the process goes into reverse.
Totality is over. The wall of darkness lifts and goes racing away to complete
its course on the earth's surface and return to space.
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- The partial phase returns. The light grows gradually
brighter. Normal service is resumed, leaving observers dazed and vaguely
relieved that, contrary to their unspoken apprehensions, the world has
not come to an inglorious end, its star devoured by unfathomable monsters.
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