As the sun goes down on another beautiful day in Joshua Tree National Park, let's stop to talk about the environmental factors that combine to create a sunset. Sunsets are impacted by the amount of particulate matter, smog, and humidity in the air. Depending on the combination of these factors, as well as clouds, haze, and other environmental factors, each sunset will produce a unique colloration and appearance. #SunsetSundays Timelapse: NPS / Emily Hassell Alt text: The sky dims in hues of pink