... Credit Copyright: Eureka by Huma-Huma Explanation: The setting is San Francisco Bay, the time is sunset, and the bridge is the Golden Gate . What you are about to see is an unexpected double sunset ending with a rare green flash . Watch closely -- in the recorded time-lapse sequence, unusually warm air created by bridge traffic refracts sunlight toward the Earth, causing a superior image of the top of the Sun to form. ... NASA Official: Jay Norris. ... Publications with keywords: sunset . ...