Science: Historic Cometary Tales

Halley’s comet and the countless others that blaze across the night skies have had a profound effect on history. They have influenced literature, art, religion and warfare, perhaps even evolution and the very beginnings of life. | For centuries comets were widely regarded as harbingers of disaster, omens of death, pestilence, wars, drought, earthquakes and floods. Modern science has dispelled many of these myths, but some persist today. In a bizarre twist, scientists themselves are beginning to attribute great cataclysms of the past to what the ancients called “hairy stars.”

The Chinese, who recorded the appearances of comets as early as 613 B.C., thought that the glowing specters were celestial brooms wielded by the gods to sweep the heavens free of evil, which then fell to earth, bringing wars, floods, droughts and other disasters.

Comets have borne that stigma ever since. Aristotle thought the night visitors were earthly “exhalations” that rose into the atmosphere and were ignited in fiery upper regions, causing drought and high winds on earth. On its pass in A.D. 66, Halley’s, in the words of the Jewish historian Flavius Josephus, “hung like a sword in the sky” and presaged the fall of Jerusalem in A.D. 70. Halley’s return in 451 was thought to portend the defeat of Attila the Hun’s armies at Chalons by Flavius Aetius.

Comets came to be so closely associated with the deaths of great leaders, says Astronomer Donald Yeomans, that historians waited expectantly for a celestial sign every time a monarch died. When the Emperor Charlemagne expired in 814 and no comet appeared, Yeomans says, “historians made one up and inserted it into history.”

Halley’s appearance in 1066, complete with a forked tail, was stitched into the renowned Bayeux tapestry, which depicted the Norman Conquest. Behind the comet’s tail, above six cringing and pointing figures (apparently Saxons), are the words THEY ARE IN AWE OF THE STAR. While the Saxons may have attributed their defeat to the comet, William the Conqueror probably forever afterward considered comets to be good omens. In 1301 Halley’s so inspired the Italian artist Giotto that in his famed nativity scene he portrayed the star of Bethlehem as a comet. The comet heralded the descent of Turkish armies on Belgrade in 1456, and in the same year was blamed for the birth of two-headed calves.

Shakespeare’s works reflect the cometary myths of the late 16th and early 17th centuries. In Julius Caesar, for example, the Emperor’s wife, after seeing a comet, warns the noblest of Romans, “When beggars die there are no comets seen; the heavens themselves blaze forth the death of princes.” But in the same play, as Cassius and Brutus plot Caesar’s assassination, Cassius says, “The fault, dear Brutus, is not in our stars, but in ourselves.”

The winds of change, however, were slow to reach Boston, where in 1682 the Puritan minister Increase Mather, awestruck by the same comet that inspired Edmond Halley, asked the members of his congregation if they would continue their evil ways “until God sends his arrows from heaven, to smite them down into the grave.”

Indeed, superstition about comets has persisted into the 20th century. As Halley’s came into view in 1910, some residents of Chicago prepared themselves for death by cyanogen-gas poisoning when, as it was widely predicted, the earth passed through the comet’s tail. As recently as 1970, Vietnamese peasants quaked at the sight of the “Sky Broom,” the unexpectedly vivid passage of Bennett’s comet.

The 20th century has spawned some notions about comets that seem even more fantastic than the ancient myths. British Astronomers Fred Hoyle and Chandra Wickramasinghe have suggested that over hundreds of millions of years, primitive biological entities, perhaps even cells, developed within some comets. These may have been delivered to the earth as the first form of terrestrial life by a comet that impacted billions of years ago. Francis Crick, co-discoverer of the DNA molecule’s structure, and Organic Chemist Leslie Orgel have proposed a less fanciful theory: Comets brought with them the chemical precursors of life, in the form of amino acids and other molecules.

That comets do occasionally strike the earth seems certain. Some scientists think a tiny chunk of a comet, exploding in the atmosphere above Siberia in 1908, caused a tremendous blast and fireball in the Tunguska region, felling trees in a 200-sq.-mi. area and knocking the nearest residents (40 miles away) off their feet.

During the past few years, evidence has been accumulating to support Physicist Luis Alvarez’s theory that a giant comet (or asteroid) struck the earth 65 million years ago, pulverizing a huge area and spewing so much debris into the atmosphere that the skies darkened for months, temperatures dipped, and much of the life on earth–most notably the dinosaurs–perished. It was the demise of the dinosaurs, many evolutionists believe, that enabled man’s tiny mammalian ancestors to emerge from hiding, occupy the environmental niches left vacant by the great beasts and other destroyed species, and evolve into Homo sapiens. Impacts by comets may have been responsible for mass ! extinctions of life at other times in the past. And scientists are certain that it can happen again.