Not long after sunset looking over the North Saskatchewan River, Alberta, Canada. Pictured by Hugo Sanchez.?The shadow of the earth itself topped by the Belt of Venus decorate the sky.?The moon rises at centre right, its rays highly reddened.?
As the sun sinks behind the camera, a large purple-blue band rises from the opposite horizon. This is the planet’s shadow cast through its own atmosphere. Above the shadow is the rosy pink glow of the ‘Belt of Venus’ or antitwilight arch.?The shadow’s upper edge is where you would see the sun just setting if you were in a high altitude aircraft. There, the sun’s rays travel a long path through the air and in particular the lower atmosphere. The direct light is scattered away by air molecules, dust and aerosol.?Blue light is scattered much more. The resulting direct rays are left richer in reds. The red light mixes with the blues of the sunlit atmosphere above. Ozone in the stratosphere adds purple-blues. The rosy pink is the mix of all this.?Those of us wintering in the northern hemisphere with its late dawns have the best good opportunities right now to see the shadow in the west before sunrise and even breakfast.??