"The Glory",or a circular rainbow spotted, while going up to the top of Zugspitze. "A rainbow gets its traditional semicircle shape from the horizon, which makes it seem as if it is half a circle. So when the same atmospheric conditions that create a rainbow are observed from an airplane or high altitude,a rainbow can appear to be a full circle. This is called a glory, which NASA defines as an optical phenomenon that “looks like small, circular rainbows of interlocking colors.”