An afterglow in meteorology are several atmospheric optical phenomena, with a general definition as a broad arch of whitish or pinkish sunlight in the twilight sky, consisting of the bright segment and the purple light.[1][2] Purple light mainly occurs when the Sun is 2-6° below the horizon, from civil to nautical twilight, while the bright segment lasts until the end of the nautical twilight.[3][4] Afterglow is often in cases of volcanic eruptions discussed,[5] while its purple light is discussed as a different particular volcanic purple light.[6] Specifically in volcanic occurrences it is light scattered by fine particulates, like dust, suspended in the atmosphere.[6] In the case of alpenglow, which is similar to the Belt of Venus,[7] afterglow is used in general for the golden-red glowing light from the sunset and sunrise reflected in the sky, and in particularly for its last stage, when the purple light is reflected.[2][1] The opposite of an afterglow is a foreglow, which occurs before sunrise