Color of Lightning

Provided and copyright by: Rick Stankiewicz
Summary authors & editors: Rick Stankiewicz

On August 2, 2007, I had the rare opportunity to safely photograph some lightning strikes near my home south of Peterborough, Ontario, Canada. I awakened to the sound of thunder at 3:30 a.m. (local time) and immediately set-up outside to photograph the lightning that was occurring to the north of me only a few kilometers away. The attached image shows the green yard light of an adjacent barnyard. Upon reviewing my images, I found that although the brilliant flashes of lightning that I saw ever so briefly as I took the picture, were in fact far more intricate than I could have ever imagined. Note the three different colors of the various branches of lightning. The main bolt is a bright white, while others are both pink and almost a purple color. Lightning also has different temperatures and hence different colors, not unlike how astronomers grade the spectral temperatures of stars using the Henry Draper Catalog (in the Kelvin temperature scale). The hotter the star (or lightning in this case) the closer to blue or white it will be. The cooler the star, the more orange to red it will be. So, all lightning is not created equal, as this photo illustrates.

A bolt of lightning can travel at a speed of 45 km/s or 160,000 km/h (100,000 mph). It can reach temperatures approaching 30,000 K (55,000 °F). This is five times hotter than the surface of our sun! No wonder lightning can cause such incredible damage. Be safe around lightning and keep your distance.