High School Students Crack the 150-Year Mystery of Angel's Glow

For over 150 years, a strange glow in the wounds of Civil War soldiers remained unexplained. Known as Angel’s Glow, the phenomenon puzzled historians and scientists alike. Now, the mystery has been solved by two high school students who uncovered its surprising cause. The eerie glow first appeared during the Battle of Shiloh in April 1862. Over two days, the conflict left 23,746 dead and 16,420 wounded. Many survivors reported that their wounds emitted a faint, bluish light at night.

Doctors noticed something unusual—those with glowing wounds healed better than others. Their injuries resisted infection and gangrene, improving their chances of survival. Yet, no one could explain why.

In 2001, teenagers Bill Martin and Jon Curtis took on the challenge. They discovered that Photorhabdus luminescens, a bioluminescent bacterium, was responsible. These bacteria live inside soil nematodes, which infect and kill insects. The microbes produce light using a set of genes called the lux operon.

The bacteria also release toxins, including one named Makes Caterpillars Floppy (Mcf), used in agriculture to protect crops. But in wounded soldiers, their secretions acted as a natural antibiotic. This prevented deadly infections, giving them a better chance of recovery.

Martin and Curtis’s research won first place at the 2011 Intel International Science and Engineering Fair. Their findings finally explained a mystery that had endured since the Civil War. The discovery of P. luminescens solved a long-standing historical puzzle. It also revealed how a tiny organism could save lives on the battlefield. Today, the bacteria’s properties continue to be studied for medical and agricultural uses.