Fireweed flowers are in peak bloom in Gustavus, Alaska, backdropped by an unusually vivid orange sun. The sun's intense color is caused by smoke filtering down from ongoing wildfires in British Columbia. Skies look red or orange during nearby forest fires because smoke fills the atmosphere with tiny particles that scatter sunlight differently than clean air. These particles are very effective at filtering out shorter wavelengths of light (blue and violet), allowing mostly longer wavelengths (red and orange) to pass through. When the Sun is already low in the sky, its light travels through more atmosphere, and the added smoke intensifies this filtering effect. The result is an eerie orange or red sky and Sun, similar to an extreme, all-day version of a sunset. Photographer: Sean Neilson