Why I chase the moon's shadow

A total solar eclipse is one of those few natural phenomena that seems to defy description.  It’s been called “awe-inspiring” and “nature’s grandest spectacle” – but the words do little to convey the actual experience of standing in the moon’s shadow.

You'll hear the phrase “once in a lifetime event" – but most people, in fact, never get to see one at all.  (Many have seen partial eclipses – but the difference between a total and a partial eclipse is literally like the difference between night and day.)

The funny thing is, in a global sense, total eclipses aren’t all that rare:  A total solar eclipse can be seen from somewhere in the world roughly once every 18 months.  But in practice, the “path of totality” – the stretch of land from which you can actually see it – is often very far from home.  (And if you stay put, and wait for a total solar eclipse to come to you, you’ll be waiting on average 375 years between each one!)  The last total eclipse visible from the contiguous 48 states of the U.S. (or from any part of Canada below the Arctic Circle) was in the winter of 1979.

And so I’ve been struggling to come up with a good analogy.  Let’s try this:  Everyone knows that sunsets at the Grand Canyon are spectacular.  And they’re pretty quick, too – it only takes the sun a couple of minutes to slip below the horizon – in the same way that the total phase of a solar eclipse lasts only a few minutes.  But now suppose that instead of happening every day, those sunsets only happened every 18 months.  And now suppose that the Grand Canyon kept moving around, so that it was only in North America a handful of times every century… are you getting the picture?  (Perhaps we can take another analogy from from the world of music -- think of the lengths that fans will go to see their favourite band -- espeically if you're worried that each tour might be the last!)

That’s why, as a teenager hooked on astronomy, I eagerly awaited my first chance to see a total solar eclipse -- an opportunity that I would finally get on July 11th, 1991.  The “path of totality” for that eclipse passed through Hawaii and Mexico (and enormous swaths of ocean).  It was also one of the longest eclipses of the century, with a duration of almost seven minutes.

I ended up joining a tour led by a group of Canadian amateur astronomers – members of the Royal Astronomical Society of Canada.  We set up our equipment in a soccer field in the small town of Santiago, near the southern tip of the Baja California peninsula.

The weather ended up presenting a challenge:  The day had started off sunny and clear – but as we got closer to totality, clouds started to build up, overhead.  (This was probably due to condensation, triggered by the temperature drop that inevitably accompanies being in the moon’s shadow.)  In the end, we it became a kind of game of hide-and-seek:  We gawked in the direction of the eclipsed sun – and relished in every second during those gaps between the clouds, when we could actually see the eclipse! 


While conditions may not have been perfect, we had spectacular views of solar “prominences” – giant plumes of gas that shoot up from the surface of the sun. 

I’ve been privileged to have seen three more total solar eclipses since then – from the Caribbean island of Curacao in 1998; from Salzburg, Austria, in 1999; and from Easter Island, in the middle of the Pacific Ocean, in 2010.


For those eclipses, I had better luck with the weather:  In Curacao, for the first time, I got to see the corona – the sun’s tenuous, pearly-while outer atmosphere, in all its glory (see the two photos above). In Salzburg (below), my friend and I climbed a hill on the north side of the Salzach, the river that flows through the heart of the city, to view the eclipse from the grounds of the Kapuzinerkloster, a 16th-century Capuchin monastery.  From this vantage point, the eclipse unfolded above the old city of Salzburg, seen across the river.  We arrived early, but before long we were joined by dozens of enthusiastic locals. 

And then, Easter Island – my last journey into the moon's shadow, before the “Great American Eclipse” of 2017.  It’s hard to think of a more exotic location from which to observe an eclipse.  Located some 3,500 kilometers off the coast of Chile, in the southeastern Pacific Ocean, Easter Island (Isla de Pascua in Spanish, Rapa Nui in the indigenous Polynesian language) is one of the most remote inhabited islands in the world.  About 6,000 people live on the island – a figure that may have almost doubled during the week of July 11, 2010.  Though the weather on Easter Island is always unpredictable, in the end it was mainly clear on the big day – and I viewed the spectacle along with a couple of hundred eclipse enthusiasts from around the world.  We watched from a grassy field beside Ahu Tahai – an ancient ceremonial complex consisting of seven stone figures (moai), on the island’s west coast.  I can’t think of a more incredible experience than watching the sun disappear from the sky, above the moai of Easter Island.

After seeing four total solar eclipses, I can understand why people get hooked.  (In fact, I may have “caught the bug” even before totality had ended, during that first eclipse back in ’91!)  And so for years I’ve been looking forward to August 21, 2017 – a date that always seemed so far away…

I’ll be in west central Oregon, near the center-line of the “path of totality,” for the Great American Eclipse.  I hope you’ll be able to see it, too.  And if not – well, there’s always the next one.  The next time the moon’s shadow strikes North America will be on April 8, 2024.  It will be here before you know it…