The Lightning Beneath Our Feet

An earthquake shook the central Italian city of L’Aquila in the early morning of April 6, 2009. In the months that followed, scientists collected dozens of accounts from people who claimed to have seen “luminous phenomena” both before and after the shock: flashes from the ground, glowing clouds, and floating balls of light that sparked like lightning.

The bizarre episodes were far from unprecedented: Time and again across history, people have reported seeing lights just before earthquakes. These lights have taken many forms: In addition to the balls and flashes seen in L’Aquila, they have