Here is a list of the 77 times that I've been touched by the wandering shadows of Earth and Moon. This personal canon of eclipses begins with an almost clouded out partial solar eclipse on October 2, 1959. On March 12, 1960, my mother promised me a lunar eclipse, but since I do not recall seeing it, that event might have clouded out also. (The eclipses that are lettered, not numbered, are events I planned to see but did not see.) However, according to this canon, I did see that eclipse – perhaps not in 1960, but when lunar saros 122 repeated itself two cycles later on April 4, 1996. (See below.)

My first total solar eclipse, on July 20, 1963, was a part of saros 145. I saw it again on August 11, 1999. When the cycles of the solar system converge again, I hope to enjoy the eclipse one more time, when it crosses the United States on August 21, 2017.

Scientists tell stories with the power to inspire. Geologists can tell a story of the titanic forces that have shaped the planet. Chemists can tell the stories of the almost infinite complexity that result from the combinations of fewer than a hundred ingredients. Physicists tell a story where the microworld of forces and interactions is based on a pleasing symmetry and unity. Biologists have their own story of unity, where the diversity of life is based on a single genetic code. The story astronomers tell is perhaps the grandest of all, since it plays out over 13.7 billion years in a universe that utterly dwarfs us.

One vital part of this story has yet to be told: the role of life in the universe. We have a high degree of confidence that the laws of physics and chemistry are universal. The visible universe contains about 1022 stars, a number so large that it's hard to grasp intuitively, and theory and observation indicate that many of them will have orbiting planets. Life on Earth is tenacious and pervasive; it's found in a bewildering array of environments, yet Earth is the only place we know of with life. That may be about to change.

Astrobiology is the scientific study of biology in its broadest context. It is a young field. Sixty years ago, we had little idea of how life on Earth started and no idea of the unity of life at a molecular level.

What is the difference between a total eclipse of the Sun and anything else Nature has to offer? All the difference in the world. A total solar eclipse, it has been said, is Nature's grandest offering. Nothing – not even for me the discovery of a comet – can approach the ecstasy that accompanies the sight of the Sun vanishing and being replaced by a jeweled crown. It's not just the appearance of the Sun transformed that does it; it appears that the rapidly dimming crescent Sun, increasingly covered by the Moon, provides a real-time dynamic event that is truly breathtaking.

The eclipse of 1918 … and of 2008

Of all the eclipses I have seen, for now I'd like to focus on just one – the eclipse of August 1, 2008. It was a repeat of the total eclipse that occurred 90 years earlier, on June 1, 1918. In a sense totality never ended that day long ago. Of course, totality could never last more than seven minutes and a few seconds for any eclipse, let alone a century, but in the minds of those who watch, the experience never ends. There is really no other way to write it; a total eclipse of the Sun is likely Nature's most incredible spectacle.

I thank Fred Espenak, Mark Littman, and Ken Willcox for the glossary they prepared for their book Totality: Eclipses of the Sun (Oxford University Press), for assistance in defining some of the terms related to solar eclipses.

Annular eclipse of the Sun. An eclipse of the Sun where the Moon's angular diameter is too small to cover the entire disk of the Sun. Thus, at the eclipse's central phase, a thin ring, or annulus, of sunlight surrounds the darkened Moon. As the Moon recedes from the Earth, more eclipses will be annular than total and, after about 600 million years, all central eclipses will be annular.

Annular-total eclipse of the Sun. If the Moon is very close to the diameter of the Sun, an eclipse that begins as annular at sunrise will turn to total when the shadow hits the full bulk of the Earth. See also hybrid eclipse.

Anomalistic month. The amount of time for the Moon to orbit the Earth, from one perigee (closest Moon–Earth distance) to the next. The amount of time is 27.55 days.

Anomalistic year. The amount time for Earth to travel from one perihelion (closest point to the Sun) to the next. That amount of time is 365.26 days.

Aphelion. When an object orbiting the Sun has reached its farthest point from the Sun, that point is called the aphelion.

Apogee. When an object orbiting the Earth has reached its farthest point from the Earth, that point is called the apogee.

In the last few minutes of a partial eclipse that will become a total eclipse, a lot of things begin to happen. The sky's gradual darkening becomes more sudden, and in the final moments the sky darkens as quickly as if someone were working a huge celestial dimmer switch. From the west, or northwest, or southwest – wherever the shadow is coming from – the sky is blackening even more rapidly. Clouds might still be visible even though there is very little sunlight left to fall on them. The Sun itself appears as a crescent so thin that it appears only as a line.

Venus appears

At almost every eclipse, between ten and seven minutes before totality begins, someone will yell a single word: “Venus!” Everyone then strains to catch a glimpse of Earth's hellish sister planet. Venus is a symbol. The sight of our neighbor world means that the sky has darkened sufficiently for the brightest planet to appear along with the crescent Sun. Along with the appearance of Venus, shadows are becoming very sharp and distinct. Just prior to totality during the eclipse of April 2005, Venus appeared due north of the Sun. The planet was near its conjunction; less than a year earlier it actually transited the Sun for the first time in more than a century.

The shadow of the Moon dropped swiftly out of the sky, charging along the sunrise terminator at 12,000 miles an hour. As the Sun edged higher, that velocity slowed to a more manageable 2000 mph as it tore southeast across the north Atlantic, crossed just west of England, and made landfall in southern France and northern Spain. The date: October 12, 1605. I like to think the event was observed by people all over Europe, including groups of people standing by the Thames in central London. Far out of town, King James I was out probably enjoying a day of hunting. As the day progressed, few let the almost imperceptible onset of a solar eclipse interrupt their business. But as more of the Moon moved across the Sun, by noon the sky was darkening noticeably and rapidly. Between 12:40 and 1:00 pm the sky was a twilight dark. Through breaks in the clouds, the Sun appeared as a thin curved line of light.

As the Moon continued moving eastward across the Sun, it abandoned its grip just after 2:00 pm. I like to imagine a group of Londoners peering at the sky as the eclipse ended, discussing its meaning. “I heard about these eclipses,” said one, “at the theatre a few weeks ago.”

“King Lear,” another nodded. “But weren't there two eclipses?” Indeed there were.

The eclipse of October 2, 1959

When I go back into the earliest of my observing records, I find that session number 1 – my very first recorded observing session – took place on October 2, 1959. That year a full total eclipse tracked by the coast of Massachusetts, and in Montreal the Sun would rise in a deep partial eclipse. It was Rosh HaShana, our Jewish New Year, and we were missing school for it, so Mom was happy to drive my brother Gerry and me to a site with a good viewing location to the east.

If seeing a total eclipse of the Sun is great, then actually photographing one must be better. Right? Not necessarily. On many total eclipses, I have advised first-time viewers not to try photography. The experience is so emotional, so engrossing, and so brief, that it would seem a waste of precious time to worry about taking pictures, especially since, if you wait a period of time, you will see professional pictures of the eclipse. It is logical advice, but almost no-one takes it. First eclipse, take a picture; that is what most people do.

So what camera should you use? What settings? If you are using film, what film is best? We begin with 10 simple rules, and then proceed by way of questions and answers based on the many queries I have heard from eclipse watchers anxious to make their first eclipse photography a successful and pleasant one.

Ten “commandments” for total solar eclipse chasers

1. (1) If this is your first eclipse, please do not try to photograph the total phase. Just concentrate on enjoying it. But since almost everyone ignores this advice …

2. (2) Never ever ever try to photograph the partial phases of a solar eclipse without filters or projection of the Sun's image. You can damage your retinas, and burn out your camera.

3. […]

Magazines

Astronomy magazine. Since its founding in 1973, Astronomy has become the world's largest and most comprehensive magazine for general astronomy. Future eclipses are presented in detail, along with maps, diagrams, and other information. Highly recommended.

Sky & Telescope magazine. Founded in November 1941, this magazine has covered virtually every aspect of astronomy, including eclipses, occultations, and transits.

Sky News magazine. The Canadian journal of astronomy, this magazine covers astronomical topics and events with a distinctly Canadian view.

Journal of the Royal Astronomical Society of Canada. Formerly a professional print journal, this journal is available online to members of the Royal Astronomical Society of Canada. Its articles cover the diversity of astronomical progress and observation throughout Canada.

Astronomy Now. The United Kingdom premier astronomy magazine. Among many other topics, this journal is filled with information about eclipses.

NASA's eclipse website (http://eclipse.gsfc.nasa.gov/eclipse.html) is a treasure trove of data and information about every solar and lunar eclipse visible for thousands of years into the past, and which will be visible well into the future. This website contains maps, contact times, exposure recommendations, and other facts about eclipses. The site was created and is maintained by Fred Espenak, who recently retired from his career with NASA's Goddard Space Flight Center.

Let's Talk Stars (http://eclipse.gsfc.nasa.gov/eclipse.html) is an internet-based radio program during which David and Wendee Levy discuss many topics related to astronomy, including eclipses.