In the Shadow of the Moon: The Science, Magic, and Mystery of Solar Eclipses

By Anthony Aveni

From an award-winning author, astronomer, and anthropologist, an exploration of the scientific and cultural significance of the mesmerizing cosmic display.

Since the first humans looked up and saw the sun swallowed by darkness, our species has been captivated by solar eclipses. Astronomer and anthropologist Anthony Aveni explains the history and culture surrounding solar eclipses, from prehistoric Stonehenge to Babylonian creation myths, to a confirmation of Einstein’s theory of general relativity, to a spectacle that left New York City in the moon’s shadow, to future eclipses that will capture human imaginations.

In one accessible and engaging read, Aveni explains the science behind the phenomenon, tracks eclipses across the ancient world, and examines the roles of solar eclipses in modern times to reveal the profound effects these cosmic events have had on human history. Colored by his own experiences—Aveni has witnessed eight total solar eclipses in his lifetime—his account of astronomy’s most storied phenomenon will enthrall anyone who has looked up at the sky with wonder.

“Aveni’s authoritative but accessible text is the clearest statement of the way our perception of eclipses has changed over the centuries.” —Stuart Clark, New Scientist

“Authoritative and engaging.” —Marcelo Gleiser, NPR’s 13.7

“A recommended way to share the spirit of the occasion.” —Laurence A. Marschall, Natural History magazine

“Everything you need to enjoy a solar eclipse—and even predict one, just like the Babylonians did! Aveni’s entertaining explorations show the very different impacts eclipses have had on past and present cultures.” —David DeVorkin, National Air and Space Museum, Smithsonian Institution 

• Language: English
• Publisher: Yale University Press
• Release date: Apr 25, 2017
• ISBN: 9780300227574

Anthony Aveni

Anthony Aveni is the Russell B. Colgate Professor of Astronomy and Anthropology at Colgate University. He helped develop the field of archeoastronomy and is known particularly for his research in the astronomical history of the Maya Indians of ancient Mexico. He is a lecturer, speaker, and editor/author of over two dozen books on ancient astronomy, and author of the children's book Buried Beneath Us: Discovering the Ancient Cities of the Americas. He lives in Hamilton, NY.

Book preview

Aveni

In the Shadow of the Moon

Aveni

Published with assistance from the foundation established in memory of

Philip Hamilton McMillan of the Class of 1894, Yale College.

Copyright © 2017 by Anthony Aveni.

All rights reserved.

This book may not be reproduced, in whole or in part, including

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ISBN 978-0-300-22319-4 (hardcover : alk. paper)

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10 9 8 7 6 5 4 3 2 1

To Ed Maxwell—wise thinker, new friend

Contents

Preface

CONTACT ONE

AN INTRODUCTION TO SOLAR ECLIPSES

1Colossal Celestial Spectacles

2Watching People Watching Eclipses

3What You See and Why You See It

CONTACT TWO

ECLIPSES IN THE ANCIENT WORLD

4Eclipse Computer Stonehenge

5Babylonian Decryptions

6Greek Science

7The Crucifixion Darkness

8Ancient Chinese Secrecy

9Maya Prediction

10Aztec Sacrifice

TOTALITY

ECLIPSES IN THE MODERN AGE

11The Rebirth of Eclipse Science in Islam and Europe

12The New England Eclipse of 1806

13Expedition to Pike’s Peak, 1878

14New York’s Central Park, 1925

CONTACT THREE

LESSONS FROM ECLIPSES

15The Eclipse as Cartographer and Timekeeper

16Zoologists Chasing Shadows

CONTACT FOUR

PERSONAL ECLIPSES

17Eclipses in Culture

Afterword: A Confession

Appendix: A Brief Chronology of Solar Eclipses

Notes

Acknowledgments

Index

Preface

Trained in the sciences, I was once too engrossed in my specialty, the astrophysics of star formation, to think much about how different cultures might interpret the cosmos. Then I took a group of students to Mexico to measure the celestial orientation of pyramids at Teotihuacan and Chichén Itzá.

By chance, I read reports in the literature about suspected astronomical alignments in sacred architecture, especially among cultures like the ancient Maya of Yucatán, and I had developed a method of precise surveying using celestial referents that caught the eyes of archaeologists. They invited me to try my techniques, and in return they taught me about the ancient peoples who watched the sky. We created a new interdisciplinary field variously called astroarchaeology, archaeoastronomy, and later (and less intimidatingly) cultural astronomy.

This fieldwork at the ancient Maya ruins in the rain forests of Central America opened my eyes to a sophisticated culture skilled in mathematics, writing, and the precise observation of nature. Our most recent work on the decipherment of a text written on a wall at the recently excavated city of Xultun in the Guatemalan rainforest proves that Maya astronomers, motivated by interests quite different from what we call science, were capable of predicting eclipses hundreds of years in advance, with minimal technology.

Modern astronomers’ questions about their ancient predecessors focus largely on aspects of the things in the sky: Did they mark sunrises and sunsets? What did they observe about the moon besides its phases? Did they predict eclipses? Did they know the world was round, that the sun is the center of the solar system, that we’re part of the Milky Way Galaxy in an expanding universe filled with galaxies like it? In other words, how like us were they? You could pose the same question about extraterrestrials.

Once I began working with archaeologists and anthropologists, I got exposed to questions of a different sort: What does another culture’s astronomy tell us about its people’s religion, their beliefs in an afterlife, the way they treat their dead? Did they practice astrology? To what end? Did the ability to predict what was about to happen in the sky over their city affect their politics? What was their concept of history? Did they believe in their cosmic myths? Such questions center around what the sky meant to them.

Cultural astronomers are more interested in what people believe about celestial happenings than the happenings themselves. Whether modern Western civilization might label these beliefs religious, astrological, superstitious, or nonscientific, understanding their perspective allowed me to hold up a mirror to my own acquired scientific view of nature as a world where things happen without regard to human affairs. I see my face in that mirror, set against a background of other faces. The minds behind them harbor alternative ways of finding meaning that make sense to them. Drawing constellations or star patterns, following the movement of planets across a zodiac, or being dazzled by a solar eclipse—experiencing the sky is not the same for everyone. As an astronomer and an anthropologist, I find most explanations about how people around the world understand natural phenomena a bit short-sighted. This book represents my attempt to broaden our collective vision. There is much to be learned, shared, and felt about the human condition from a deeper exploration of the natural world seen through diverse human eyes.

In the Shadow of the Moon is a personal narrative that tells as much about people who have watched eclipses as the eclipses themselves. I was motivated to craft this book for publication in 2017 because, after experiencing a ninety-nine-year eclipse drought, mainland North America is on the verge of witnessing two transcontinental total eclipses of the sun. The twin eclipses positioned just over the American horizon offer an ideal prompt. If two minutes of dramatic daytime darkness generated more than one hundred articles in the New York Times in January 1925, imagine the attention that will attend seven minutes of totality spread seven years apart in large swaths centered on the middle of North America between 2017 and 2024.

I’ve been the fortunate witness of eight total eclipses of the sun, bringing me to diverse places ranging from Canada to the South Pacific, across Atlantic waters off the coast of Argentina, to the Egypt-Libya border and the middle of the Black Sea. Despite all this travel, I’ve logged less than half an hour in the complete darkness of the shadow of the moon. This is far from record breaking, and any amount of time is never enough. If you’ve already witnessed a total solar eclipse, you know what I mean.

CONTACT ONE

An Introduction to Solar Eclipses

•  •  •

Aveni

(Overleaf): Contact I / Begin Partial (© 2008 Fred Espenak, MrEclipse.com)

1

Colossal Celestial Spectacles

These late eclipses in the sun and moon portend no good to us: though the wisdom of nature can reason it thus and thus, yet nature finds itself scourged by the sequent effects. Love cools, friendship falls off, brothers divide: in cities, mutinies; in countries, discord; in palaces, treason; and the bond cracked between son and father. This villain of mine comes under the prediction; there’s son against father: the king falls from bias of nature … ’Tis strange!

—William Shakespeare, King Lear, 1606

Studying the sky has made me realize what sheltered lives we lead. Efficient central heating and air conditioning signal our preference for being indoors. Most of us labor indoors, shop and dine indoors, work out and play tennis indoors. Our eyes spend most of their waking hours scanning computer and phone screens. We tan without exposing ourselves to the sun and, mindless of its daily course, we look instead at our watches to tell time and set appointments electronically. Think of the inconvenience the last time you experienced a power outage.

Living in such a world, we tend to dwell on the gains technology has afforded us: instant news, fresh food, the ability to move rapidly from place to place. But technology isn’t the only reason we severed the links between daily life and the physical world around us. A change in the basic way we think about nature contributes to our detachment from it. The divorce from the world around us began five hundred years ago during the European Renaissance and continued through the late eighteenth-century Enlightenment, when nature was reintroduced to culture as a world apart from human affairs. Like the earth, the sky, once alive to our ancient ancestors, came to be regarded as inanimate matter, possessing neither soul nor meaning. Western society attempted to objectify the universe, making it an entity to be described and understood as it is or for its own sake. Consequently, whatever dialogue we once had with nature was silenced.

When we do encounter the world outside, we tend to cast our eyes downward, ignoring half our visual field, which lies above eye level, bounded by the horizon that surrounds us. But who needs the sky, anyway? What incentive is there to know the constellations, the phase of the moon, or the point where the sun popped up over the horizon this morning? Today the look of the sky is little more than an imminent weather indicator. Shall I take an umbrella? And when any of us contemplate a recreational peek at the heavens, we dig instead into our techno-devices, like the apps that allow us to track the stars from the comfort of a basement apartment.

But for most of human history, the sky was relevant. People paid attention to the rising and setting sun, the phases of the moon, the coming and going of each of the planets. The relative perfection of the firmament beckoned for human connection. The first crocus might arrive a bit late, the last snowfall a little early, but I know that when Arcturus, the brightest star in the northern hemisphere, makes its first annual appearance in the east after sunset, it’s my birthday. The sky became the logical medium to mirror the ordered lives our species strove to lead. For ages it would serve as the storyboard for morally based tales of heroism and adventure. From season to season, people found meaning in the dance of the cosmic denizens who resided in the world above.

Every once in a while, something extraordinary happens up there, grabs our attention, and reconnects us. Comets belong to my personal colossal celestial spectacles, like the comets Ikeya-Seki in 1965, West in 1976, Hyakutake in 1996, and Hale-Bopp in 1997. (Halley’s Comet was a bust in 1986, but on its previous close passages in 1835 and 1910, it took over the heavens and the headlines for weeks.)¹

Most comets are unpredictable. Formed in the far reaches of the solar system, they appear suddenly seemingly out of nowhere, streaking slowly from night to night across the starry background, most of them never to return. That’s probably why throughout history, comet appearances were thought to portend ill fortune, unscheduled events that disturbed the otherwise pristine, predictable happenings in the quintessence. Julius Caesar’s assassination coincided with the appearance of a comet. The comet of 1316, visible across northern Europe, was said to have been a sign of the Great Famine of 1315–17, which killed 10 percent of the population. (The extreme weather known as the Medieval Warm Period was more likely responsible for the event.) The great comet of 1843, visible as a luminous streak across the western sky for several weeks following sunset, was heralded by a religious sect that would later grow into the Seventh-day Adventist Church as a sign in heaven that the Apocalypse described in the Book of Revelation was surely at hand. And when Halley’s Comet appeared in 1301 (it wasn’t yet known to be recurrent), Giotto imaginatively represented the Star of Bethlehem as a comet in a nativity painting on the ceiling of the Scrovegni Chapel in Padua, Italy.

How bright a comet will become (and when) is difficult to predict. It depends on its distance from the earth and how close it gets to the sun. Comets shed their gaseous shroud in the form of a tail that grows to millions of miles in length. Not all comets possess the same blend of dust and gas: lots of dust and you get a faint comet, less and you get a much brighter one due to the sun energizing the molecules that light up its gaseous atmosphere.

In 1965, as a young astronomy teacher in Hamilton, New York, I remember driving to the Colgate University Observatory for the anticipated pre-dawn view of Comet Ikeya-Seki. Turning onto the main campus road and veering toward the observatory, I noticed several pairs of headlights swarming over the dew-covered grass in the darkness. Other vehicles were parked along the crowded roadside all the way down the hill. A few dozen people milled around the tiny oracle housing our telescope, eagerly awaiting instructions about which way to direct their gaze. Some of my academic colleagues made skeptical inquiries, an attitude well cultivated in their trade. There were a couple of excited kids who aspired to be astronauts, growing up in the mid-1960s when America’s space program was just beginning. Would the comet inspire them?

Though we persevered morning after morning for several days, we saw very little except for a faint fuzzy patch at the predicted position. Then, thinking the comet a dud, everyone gave up. About three weeks after predicted maximum, I awoke just before dawn with a start. Our four-year-old had toppled out of bed. Once I got up and repositioned her, I thought: why not take a look outside? I stepped out into the chilly autumn air, and there it was, an extraordinarily bright fuzzy object just above the faintly twilit eastern horizon. Ikeya sported a long, curved luminous tail that arced almost all the way up to the overhead point. Never had I seen nature conjure up a sight like that; it just didn’t seem to belong in a starry sky. Ikeya was by any account a colossal celestial spectacle! To this day it remains the second best wonder I’ve ever witnessed in the sky. Unpredictably, the comet turned out to be more of a sun grazer than orbital pundits had anticipated. In fact, it passed so close to the sun that it was captured and locked into an elliptical orbit. It’s due back in 2064.

In our scientific age, we’ve been taught rational explanations for rare cosmic events, yet we are still provoked by nature’s bias, as Shakespeare wrote. We are still surprised, awed, and maybe even a bit unsettled, as was I by Ikeya years ago. People still wonder: can there be a message that accompanies this fractious cosmic behavior?

Securing omens from heaven lives on in popular segments of American culture. I vividly recall Comet Hale-Bopp playing the role of extraterrestrial messenger three decades later on the eve of the third millennium. Leaders of the Heaven’s Gate cult sought signs from above that the destruction of the world was imminent, at a time when thoughts about the end of the world in general were on the increase.² They believed Hale-Bopp was being trailed by a space vehicle inhabited by descendants of ancient astronauts who had originally placed our human ancestors on earth. Now they were returning to reap the harvest, those who had sacrificed themselves to get to the next step in the universal course of galactic civilization. Between March 24 and 26, 1997, thirty-nine members of the group donned identical shirts, sweatpants, and shoes. They drank a phenobarbitol-laced concoction to prepare for the anticipated cosmic boarding. Days later, police found their dead bodies. Comets can have a profound effect on people.

Meteor showers are high on my list of colossal cosmic events. The sun eventually destroys comets with closed orbits, particularly short-period ones. The disintegrated debris of these worn-out comets becomes seasonal storms of shooting stars when the earth crosses their orbits, the Quadrantids in early January, the Leonids in mid-November, the Geminids in mid-December. Most famous among the showers are the summertime Perseids, which dart in all directions out of a radiant point in the constellation of Perseus during mid-August. On a moonless night, especially after midnight, when our part of the world meets the swarm head on, you can count up to a hundred of these luminescent yellow-white streaks in just an hour, some up to dozens of moon-widths long, each lasting for a few seconds. I remember instinctively anticipating the pop of a Roman candle sound as each meteor trail faded.

The Leonids become especially active at thirty-three-year intervals, when the earth crosses the portion of the orbit where the defunct comet’s remnants are most heavily concentrated. The 1833 storm rained down close to 30,000 meteors an hour. The meteors fell from the elements on the 12th of November 1833 on Thursday in Washington. It frightened the people half to death, wrote one diarist.³ Astronomy historian Agnes Clerke compared their intensity with what you might see during a mild snowstorm: The sky scored in every direction with shining tracks and illuminated with majestic fireballs.⁴ Frederick Douglass and Harriet Tubman witnessed and wrote about the great Leonid shower of 1833, as did the founder of the Mormons, Joseph Smith, who interpreted the storm as a sure sign in the sky that Jesus was about to descend from heaven.

Occasionally a super meteor, or bolide, will flash unpredictably out of nowhere. In Chelyabinsk, Russia, on February 15, 2013, a streaking flash lit up the morning sky brighter than the sun; it exploded near the horizon after a few seconds. The shockwave knocked out windows in several houses and buildings and left a sulfurous smell. The twenty-yard-diameter asteroid fragment responsible for the blast was estimated to weigh upward of 10,000 tons. You need to be in the right place and facing the right direction to witness a bolide. Recently, while talking to one of my students on the campus quad following our early afternoon class, I saw his face light up. His jaw dropped as he pointed over my right shoulder. By the time I turned around, all I could see was a remnant smoke trail running from the top of the sky down toward the horizon. As I said, you need to be lucky.

The northern lights deserve a high place on anyone’s list of nature’s celestial extravaganzas. The dazzling shows they put on are semi-predictable, occurring most often a day or two after hot flares erupt on the sun’s surface. Incoming solar electrons and protons collide with molecules and atoms at the top of our atmosphere, causing them to glow. Drawn along the earth’s magnetic field lines toward the poles, the particles create a display of shifting, pulsating curtains of colored light: green and blue from activated nitrogen molecules, red from oxygen atoms (you can find a host of displays on YouTube).

Because I happen to live in a favored location relatively close to one of the magnetic poles, I’ve had several opportunities to witness the aurora borealis, the northern dawn. I know I’m in for a show once I spot that whitish-green glow near the north horizon. Greenish bands develop into curtains that start to ripple as if blown by the breeze; then they break down into arcs, only to re-form. In one unusually strong display, I saw bright crimson rays emerge from a focus near the overhead position. They dissolved into pulsating arcs that seemed to shower down on me, the funneling of charged particles along the magnetic field lines. After half an hour the colors faded, but they became reactivated an hour or two later.

Contemporary Inuit people of northeast Canada call the northern lights aqsarniit, after the celestial football players who, they say, make it happen. An old Inuit man described the impression he had of the aurora in his youth in animate terms. He believed his actions could influence what happens in the heavens: "I have heard that they used a walrus head for a football. … I have not heard what the aqsarniit are made of but you can hear the swishing sound they make. If they get too close you can chase them away by twisting your tongue to the upright position. We used to do this when the aqsarniit got too close and it always had an effect. When one was watching them you could see them getting closer and closer until one could hear the swishing sound. At the same time they would be moving sideways also making this sound."⁵ Scientific narratives of dazzling celestial phenomena like these usually include an abundance of detailed explanations of the physical causes behind the visual effects. Little attention gets paid to exactly what is felt by those who thrill to them.

Rainbows, halos around the sun and moon, lightning strikes in the distance that illuminate the night sky, comets, meteors, the aurora—all are high up on my personal list of colossal celestial spectacles. But of all the wonders of the sky I have ever marveled at, none came close to surpassing the transient, exquisite beauty of a total eclipse of the sun.

2

Watching People Watching Eclipses

Nothing can be surprising any more or impossible or miraculous, now that Zeus, father of the Olympians has made night out of noonday, hiding the bright sunlight, and … fear has come upon mankind. After this, men can believe anything, expect anything. Don’t any of you be surprised in [the] future if land beasts change places with dolphins and go to live in their salty pastures, and get to like the sounding wave of the sea more than the land, while the dolphins prefer the mountains.

—Greek poet Archilochus, seventh century BCE

Storm chasers deliberately pursue severe weather conditions, especially tornadoes. The term dates back to the 1950s, though it didn’t enter American pop culture until television programs focused on the scientific value of collecting data in the eye of a storm in the late 1970s and early 1980s. Later, its potential for extreme recreational activity surged. The 1995 box office hit Twister, which followed storm chasers-cum-meteorologists testing their competing devices during a rash of storms in Oklahoma, further romanticized the dangerous activity.

The desire to live on the edge, to get as close to danger as you possibly can simply for the thrill of it, compels adventure-seeking extroverts to engage in extreme sports, such as rock climbing, BASE jumping, and reaching the peak of Mount Everest. These same tendencies can be seen in storm chasers, motivated by the pull of nature—as one journalist put it, to see something magnificent that you can’t possibly control.¹ Recreational storm trackers love photo-documenting the biggest, the strongest, often the most damage-inflicting weather events. Risk-oriented travel companies offer chase tour services; not surprisingly, they attract people who live mostly outside the Tornado Alley states, including people from other countries. A typical tour will pick you up at the airport (in season, of course), supply you with ground transportation, lodging, food, snacks, video highlights, a T-shirt, and souvenirs. Participants tell stories of the tension they experience waiting out incipient danger and the devastating letdown that follows when they fail to sight a storm or, worse, chase one only to miss getting close enough to document it.

But storms aren’t the only natural phenomena adventurers lust after. Eclipse enthusiasts abound. A popular eclipse website predicts: People from all over the world [will] begin to converge on the United States [in August 2017]. Except for people returning home, visiting family, or conducting business at what happens to be just exactly the right time in history, these will be people who make it a point to travel to wherever the moon’s shadow is going to touch the earth, and position themselves in a spot carefully chosen—sometimes years in advance—to ensure they see the sight.²

The people referred to are the eclipse chasers. They are after a different kind of thrill, and they have been around far longer than seekers of the storm. Eclipse chasers acquired their contemporary moniker from a 1914 New York Times article describing an early attempt by Amherst College astronomy professor David Todd to view totality from an aeroplane, saying that he was chasing the sun.³

Today, a host of websites unite the questers of the lunar shade; for example, the website Eclipse-Chasers.com calculates eclipse events and logs observations from contributors. Bill Kramer, who created the site, is an engineer, a computer applications developer, and an avid amateur astronomer. (He is also a lecturer on astronomy-related theme cruises.) The site’s Eclipse Chaser Log lists the number of eclipses experienced, totality time, partial eclipse time, and the chase success percentage of 220 entrants. At this writing, the record holder in this competitive cosmic sport is Williams College astronomer Jay Pasachoff, with sixty-four eclipses, thirty-two of which were total (tied with another entrant). Pasachoff has experienced 1h19m31s of totality and a total of 143h14m28s under the influence of the shadow, counting partial eclipses.⁴ Extreme eclipse competitors try to prolong their totality time by literally chasing the eclipse, flying in the same direction as the shadow, which travels across the surface of the earth at nearly two thousand miles per hour. In 2010, along with twenty-three others, commodities trader Rick Brown chartered a jet that traveled five hundred miles per hour, allowing him to extend his time in the shade by four minutes.⁵

Aveni

Projected paths showing locations to view total solar eclipses including the twenty-first-century great American eclipses. (Permission to reproduce from Exploratorium, www.exploratorium.edu. Basemap data © OpenStreetMap contributors [CC BY-SA].)

I am an eclipse chaser and I travel all over the world. You may think I’m crazy. I prefer interesting, reads one T-shirt available on Eclipse-Chasers.com. The serious umbraphile thinks nothing of shelling out vast sums of money to bask for only a few seconds in totality. He usually gets hooked when a friend shows him pictures of her own experiences under the shadow and persuades him to join in her next venture. It also helps if you’re the gregarious type with an appetite for exotic food.

We always manage to talk ourselves into going no matter how expensive it is, said a couple