Comets have always aroused excitement—sometimes fearful, sometimes joyous. Today, we await Comet ISON, wondering how brightly it will appear in the sky. But today is also Halloween, and we are also inclined to think about comets’ spooky past. Five hundred years ago, when a comet appeared, we probably would have been pretty freaked out.
In the 17th century, many people believed comets were omens of terrible things to come. They understood the regular motions of the stars and planets, so the sudden appearance of a comet was worrisome, to say the least. For many people, a comet predicted impending war, storms, plague, and violent death.
This German broadside, or poster, features three “divine torches of wrath” on a death clock. The clock’s hands—the comets of 1680 (the largest), 1682, and 1683—point to frightening numbers constructed of bones and weapons. In the central image, three horsemen of the apocalypse ride outside the city of Augsburg while the comets flash across the sky. From left to right, the horsemen represent war (dressed in armor and carrying a sword), death (a corpse carrying a scythe, like the Grim Reaper), and famine (bringing scales to measure bread or grain). The text below the image describes misery, pestilence, and destruction. The broadside would have announced these possible misfortunes to the public on the streets of Augsburg.
Here, the Comet of 1680 (or Kirch’s Comet) has gruesome implications, but later it helped astronomers understand much more about comets. Gottfried Kirch observed the comet with his telescope on November 14, 1680. In fact, it was the first comet discovered telescopically. The comet was visible to the naked eye into February, and Isaac Newton tracked it with his telescope until March 19, 1681. Newton and John Flamsteed, who had recorded the most accurate observations of the comet, corresponded extensively about cometary motion. Using Flamsteed’s observations, Newton developed a technique for determining the orbit of comets. Soon after, Edmund Halley modified Newton’s method and predicted the 1758–1759 return of the comet of 1682 (also shown on this broadside).
The Adler's collections contain many examples of humankind’s attempts to understand celestial phenomena. Comet broadsides, celestial charts depicting locations of historic comets, rare books on comets, and the occasional comet-related scientific instrument show the evolution of our quest to understand these events. The Adler’s comet holdings are the second most significant collection of such materials in the world.
Today, we anticipate—without fear—the arrival of Comet ISON. Stay tuned to the Adler for further comet developments. Follow the conversation online with #CometISON.
Written by Jodi Lacy, archivist and digital projects manager at the Adler Planetarium.