Pliny's Burning Shield: The Sparking Object Over Rome in 100 BCE

Pliny the Elder records a burning, sparking shield that crossed the sky at sunset from west to east in 100 BCE.

Pliny the Elder's Natural History records that in 100 BCE a burning shield, scattering sparks, ran across the sky at sunset from west to east. Astronomers say it fits a bright fireball meteor.

Pliny the Elder's Natural History, finished around 77 CE, is an encyclopedia of everything the Romans knew about the world. Book 2 covers the heavens and the weather, including comets, meteors and other lights seen in the sky. One short entry has become famous. Pliny collected reports from hundreds of earlier authors, and he often names the year an event occurred.

In the Bostock and Riley translation: "In the consulship of Lucius Valerius and Caius Marius, a burning shield, scattering sparks, was seen to run across the heavens, at sunset, from west to east." Romans dated years by their two consuls, and Lucius Valerius Flaccus served with Gaius Marius in Marius's sixth consulship, which places the sighting in 100 BCE.

Pliny files the event among other named phenomena: beams of light, torches, and burning shields (clipei ardentes) were categories in ancient weather lore, much as modern observers classify fireballs and bolides. In the same part of his work he reports blood-red skies, stones falling from heaven and several suns seen at once.

For UFO writers the attraction is the specificity: shape, color, sparks, time of day, direction of travel and a firm year. Astronomers note that the description fits a bright fireball, a meteor that breaks up and leaves sparks as it crosses the sky. The west-to-east path at sunset is not unusual for such an object. What remains striking is how carefully the Romans logged it.