I could never have anticipated what would happen when I took my grandson, Max, to see his first eclipseby Frank Close / September 6, 2017 / Leave a comment
I waited 45 years for my first total solar eclipse before finally seeing it on 11 August 1999, in Cornwall. It was cloudy.
Solar eclipses are repeated every 18 years, 10 and 1/3 days, which brings us to 21 August 2017. The one-third is important: in that extra 8 hours the Earth spins eight time-zones. So instead of Cornwall, this time I headed for the western United States and the so-called “Great American Eclipse.” I decided to take my 7 years old grandson, Max, as he would be the same age as I was, long ago, when my teacher showed me a solar partial eclipse and inspired my lifelong interest in science.
After that first experience, I was hooked, and began the long wait for that first total eclipse in 1999. Since then I have seen five more, in exotic locations ranging from the Sahara Desert in Libya to the South Pacific Ocean. I have written about them in Prospect, and in anticipation of the Great American Eclipse of August 2017, told my story in Eclipse: Journeys to the Dark Side of the Moon. That tale concluded with our preparations as we set off for the USA. How would Max react to the experience which had meant so much to me all those years ago? I could never have anticipated what actually happened.
2000 meters up in Teton Village, Wyoming, the sky was clear. Everything was in place for us to witness the beauty of a natural coincidence. For that is precisely what eclipses are: the moon is 400 times nearer to us than the sun, and is also some 400 times smaller than it in diameter, which means that if it passes in direct line of sight, it will totally eclipse the bright solar disc.
It has not always been thus. The natural chronometer of eclipses is so precise that it is possible to calculate dates and times of past examples to the second. When Edmund Halley first did this in the 18th century, he discovered a discrepancy with the written records—and the further back in time he went, the larger the mismatch became. The reason is that Halley had assumed the Moon follows the same elliptical orbit repetitively through the ages whereas, we now know, it is in fact gradually receding…