How Two Teens Solved the 150-Year Mystery of Angel's Glow

A strange glowing light appeared on the wounds of soldiers after the Battle of Shiloh in 1862. For years, the phenomenon—dubbed Angel’s Glow—remained unexplained. Decades later, two high school students uncovered the scientific truth behind the mystery. The Battle of Shiloh, fought over two days in April 1862, left 23,746 dead and 16,420 soldiers too wounded to move. Many survivors reported seeing a faint blue-green glow emanating from their injuries. Despite the harsh conditions, those with the glowing wounds suffered fewer infections and cases of gangrene.

In 2001, teenagers Bill Martin and Jon Curtis began investigating the mystery. They discovered that the glow came from *Photorhabdus luminescens*, a bioluminescent bacterium. This microbe lives in soil nematodes and produces light through a cluster of genes called the *lux operon*. The bacteria’s secretions also possess antibiotic properties, which likely protected the soldiers’ wounds from infection. However, *Photorhabdus luminescens* thrives only at lower temperatures—explaining why the glow rarely appears in humans, whose body heat would normally kill it. The cool, damp conditions of the battlefield allowed the bacteria to survive and multiply. Their research earned Martin and Curtis first place at the 2011 Intel International Science and Engineering Fair, finally solving a Civil War mystery that had puzzled historians and scientists for over a century.

The discovery of Angel’s Glow revealed how a rare combination of bacteria, weather, and battlefield conditions saved lives. The findings also highlighted the unexpected ways nature can influence human survival. Today, the phenomenon remains a fascinating example of science hidden in history.