What is that band of color in the sky? It's known as the "Belt of Venus," more technically known as an antitwilight arch. This phenomenon is often visible shortly before sunrise or after sunset when the sky is clear and, especially, when there is an open view of the distant horizon. The dark band immediately above the horizon is Earth's shadow, projected into the atmosphere. Above it, you can see the reddish portion of the solar spectrum, diffracted (bent) by the atmosphere.