The Belt of Venus

Ever seen a sunset or sunrise with a pink or purple colour? Surely you have seen it, this is the so called Belt of Venus and it might be less spectacular than the bright and colourful sunsets of orange of red colours, however the Belt of Venus is an atmospheric phenomenon, in fact what happens is that we see our own Earth's shadow projected in the sky.

This phenomenon can be seen in two occasions, during the sunrise and at twilight. Shortly after the sunset or just before the sunrise, the observer is surrounded by a pinkish glow (or Twilight Wedge) which extends for about 10°or 20 ° above the horizon.

The Belt of Venus seen in Faro, Portugal. Photography: Joaquín Galán.

Often, the glow is separated from the horizon by a dark layer, which happens to be Earth's shadow or "dark segment." The arch's light pink color is due to backscattering of reddened light from the rising or setting Sun. A very similar effect can be seen during a total solar eclipse. 

The name of the phenomenon alludes to the cestus, a girdle or breast-band, of the Ancient Greek goddess Aphrodite, customarily equated with the Roman goddess Venus.