What is Saint Elmo's fire?

Saint Elmo's fire refers to the visible discharge of static electricity. This phenomenon occurs during thunderstorms or in conditions of very high electrical field strength, such as during severe weather or when flying through a thunderstorm. It appears as a bluish or violet glow at the tips of objects, such as the wings of an aircraft or the masts of ships, indicating a strong electric field in the surrounding atmosphere.

The phenomenon is named after St. Erasmus of Formia, the patron saint of sailors, and has historically been associated with the presence of an electrical charge. Pilots and mariners have noted this visual effect for centuries, often as a sign of storm activity or high atmospheric electricity.

While other options mention elements related to electricity, Saint Elmo's fire is specifically characterized by its visible manifestation of static discharge rather than any measurement techniques, components of electrical systems, or classification as lightning. Understanding this unique phenomenon helps individuals recognize atmospheric electrical activity and its implications for safety in aviation and maritime contexts.