Originally published 30 August 1999
It was a long way to go for two-and-a-half minutes of darkness.
On August 11 [1999], 800 avid eclipse chasers, including a high-tech team from NASA, waited on a ship in the Black Sea for a total eclipse of the sun.
Our location offered several advantages: first, it was close to the place of maximum eclipse duration; second, it had a better-than-average chance of clear skies; and third, the ship’s mobility made it possible to seek a hole in the clouds in case of spotty weather.
The moon’s shadow first touched Earth in the Atlantic Ocean south of Newfoundland, then swept eastward across the southwestern tip of England, central Europe, the Black Sea, Turkey, Iraq, Iran, Pakistan, and India — a racing dot of darkness on the face of the globe.
The lucky people of Stuttgart, Munich, and Bucharest could sit in their back gardens and watch this most spectacular of nature’s phenomena — if skies were clear, which they weren’t over much of Europe — but the rest of us had to make a journey to a faraway place. Many lifetimes might pass without a total solar eclipse happening in the place where we live.
Most people will know why solar eclipses happen: The moon blocks the sun’s light. What is less well understood is why total solar eclipses are so rare.
Think of the Earth as a grapefruit. On the same scale, the moon would be a grape about 20 feet away. The moon moves around the Earth in an almost perfectly circular orbit, but the Earth is not quite at the center of the circle. Sometimes the moon is a bit farther from the Earth and sometimes a bit closer.
Like every object in the solar system, the moon casts a conical shadow that points away from the sun. The moon wears its permanent shadow — lunar night — like a long, thin wizard’s cap. To have a total eclipse of the sun, some part of the Earth’s surface must pass within that shadow.
Now here’s the kicker: The moon’s shadow is almost exactly as long as the average distance of the moon from the Earth (think of the grape with its 20-foot-long shadow tapering to a point). When the moon is near apogee — its greatest distance from Earth — the shadow does not quite reach the Earth and a total eclipse cannot occur. When the moon is near perigee — its nearest distance to Earth — the thin tip of the shadow can reach the Earth, or even extend a bit beyond it.
This time, the intersection of the shadow with the Earth’s surface was a nearly circular oval about 60 miles wide.
If the moon were a bit smaller or a bit farther away we wouldn’t have solar eclipses at all. And if the moon were bigger or closer the intersection of Earth and shadow would be larger and eclipses wouldn’t be quite so rare. By a curious celestial coincidence, the relative sizes and distances of sun and moon are such that we are graced with an extraordinary event that is deliciously rare.
During the next decade there will be only six total eclipses of the sun, and each of them will require a substantial journey.
June 21, 2001. The shadow will sweep across equatorial Africa. Many people will be waiting on ships in the Atlantic Ocean off the coast of Angola, near the place of maximum duration.
December 4, 2002. Maximum eclipse duration will occur in the South Pacific, although the beginning and end of the eclipse will touch Africa and Australia. One spot on the coast of Angola will experience maximum duration two years in a row.
November 23, 2003. The frozen continent of Antarctica will see the eclipse.
March 29, 2006. Maximum eclipse duration will be in the Sahara Desert, but a fleet of cruise ships will be waiting in the eastern Mediterranean Sea off the coast of Egypt.
August 1, 2008. Siberia is the destination.
July 22, 2009. Eclipse chasers will head for Shanghai.
Not until 2017 will the tip of the moon’s shadow sweep across the United States.
In former times most people lived and died without witnessing a total solar eclipse. In this day of convenient and relatively inexpensive travel, no one should miss the chance to see a total solar eclipse at least once, which was why I was on that cruise ship in the Black Sea with 800 other people.
The shadow of the moon sliced across the Earth’s surface like the tip of a fencer’s blade. We were waiting in a calm sea under cloudless skies when the oval of darkness raced over us, extinguishing the sun’s light for two-and-a-half minutes.
With a last blaze of glory — like the gem of a diamond ring — the sun’s disk appeared to become jet black. Streaks of silver radiance streamed outward into a blue-black sky, and crimson flecks marked solar storms leaping beyond the rim of the covering moon. Venus blazed nearby. The horizon all around was rosy with a midday dawn.
When the sun went dark, 800 jaws dropped and eyes gaped wide. The Second Coming could hardly have evoked more awe.
Was it worth traveling thousands of miles to see? You bet.
