two cats on a brick wall over sunset

[, also called sundown in some American English dialects, is the time at which the Sun disappears below the horizon in the west. It should not be confused with dusk, which is the (variously defined) point at which darkness falls, some time after the Sun itself sets (which begins twilight).The red hues of the sky at sunset are caused by the Rayleigh scattering of blue light by atmospheric dust. Relatively little red light is scattered in this way, and so the sky often takes on shades of red, orange and yellow. The color of a sunset may be enhanced by atmospheric phenomena such as clouds, smoke and smog produced by natural processes or human activity, and by ash from volcanic eruptions. A number of eruptions in recent times, such as those of Mount Pinatubo in 1991 and Krakatoa in 1883, have been sufficiently large to produce remarkable sunsets (and sunrises) all over the world. See more at Wikipedia.org...]