Chasing eclipses offers thrills of a lifetime

Picking out which eclipses to chase is easy.  In fact, eclipses are great for folks who like to plan ahead: the exact time, location and length of every eclipse out to the year 5000 has already calculated, most notably on the Web site of NASA’s Fred Espenak, the patron saint of eclipse chasers.  So picking a great total to view isn’t that hard.  What’s hard is deciding where to view it. 

That’s because when you view a total solar eclipse, you’re standing in the shadow that the moon is casting on the earth. During the course of the eclipse, that shadow usually travels a few thousand miles across the earth’s surface — but is only, on average, a hundred or so miles wide at any moment in time. And for maximum length of darkness, you want to be standing in the very center of that shadow at a certain point on the path. 

But it’s not that simple: you have to worry about the weather. Years before every decent total solar eclipse, eclipse chasers start to talk about the weather — specifically, expected percentage of cloud cover all along the path. The last thing you want is to travel half-way around the world and have clouds obscure the view. It will still get dark and eerie, but if you plan to do any astronomy, you’re out of luck. 

The weather research and debate gets intense and highly detailed several years before the actual event.  For this week’s eclipse, for example, a Canadian even posted the last 15 years of satellite images of North Africa and the eastern Mediterranean for March 29.  It’s generally agreed that the Libyan desert has the best prospects for clear skies (assuming no dust storms) but concerns over visa availability moved some eclipse chasers north to Egypt.  For those who like more comfort — but slightly worse odds on clouds — the southern coast of Turkey is going to be popular.  I’m heading for the central plateau region of Turkey called Cappadocia — if we get clear skies, the higher elevation away from coast will provide very sharp viewing. 

So who will actually make the trek to Libya, Egypt or Turkey? Over the years I’ve met three categories of eclipse chasers.  First are the real astronomers, professional and amateur, who come to every eclipse laden with boxes and boxes of optics and equipment — costly, delicate and obscure gear that invariably provides hours of interesting discussion with customs inspectors.  But for them it’s worth the trouble: a total eclipse is a rare natural opportunity to do viewing that is impossible under any other circumstance. Most famously, Einstein’s general theory of relativity was proven during a total solar eclipse in 1919. 

The second set of eclipse chasers are the photographers — often hard to distinguish from the hardcore astronomers, because they lug plenty of optics as well. But what they’re really looking for are great pictures: totality itself, as well as moments like the “diamond ring effect” as sunlight just begins to stream out around the side of the moon. This is high-stakes photography: miss one shot and you have to wait a few years to try again.

And then finally, there are the addicts, who are just looking for the experience. The heaviest optics I take is a pair of 7 x 42 binoculars; when nearby astronomers take pity on me and offer a precious glance through their scopes, I’ll look — but then I want to step back and get the big picture.

In the Australian outback, I watched an astrologer gather small rocks during the darkness of totality and put them into an inlaid box, never to expose them to light again. At an eclipse at a huge Stonehenge replica in the Columbia River valley I joined a group of druids dancing to regrettable guitar music. And in the Baja desert a young couple in a jeep invited me to go up into the foothills to watch the total from a marijuana field they’d discovered. During my last total — which in an unusual departure from form passed over five islands in the Caribbean — I spent the entire three minutes floating on my back in the ocean, a quarter mile off-shore.

I still don’t know what I’ll do during this week’s total. We’re watching from a little village known for its spiritual forbears and dervish traditions, so perhaps a mystical mood will ensue. Or maybe we’ll be “zipped out” by unlucky cloud cover. If so, it won’t be the end of the world.  I’m already planning for the next really good total, a 6 minute 39 second beauty in July, 2009, visible across most of China. 

And perhaps in the end that’s another appeal of eclipse chasing: It ties your life to the celestial clockworks in a very big way. You soon learn, for example, that eclipses run in families known as Saros cycles — each family member separated by the approximately 18 years it takes for sun, moon and earth to return to the same relative positions in space.

Saros family 136 has produced the best eclipses of both the last century and this one, since all of its members are six minute plus events. It was a Saros 136 eclipse that helped prove Einstein’s theory in 1919. It was a Saros 136 eclipse that hooked me in the Sahara. And with some luck, a Saros 136 eclipse will be my last great total, in my native state of California, clocking in at just over six minutes on August 12, 2045. In fact, if you happen to be at that eclipse, look for me. I’ll be the wizened old guy with the binoculars, grinning like crazy. 

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