Gegenschein

[1] Gegenschein is distinguished from zodiacal light by its high angle of reflection of the incident sunlight on the dust particles.

[4] It is commonly stated that the gegenschein was first described by the French Jesuit astronomer and professor Esprit Pézenas [fr] (1692–1776) in 1730.

Further observations were supposedly made by the German explorer Alexander von Humboldt during his South American journey from 1799 to 1803.

Humboldt's report instead described glowing triangular patches on both the western and eastern horizons shortly after sunset, while true gegenschein is most visible near local midnight when it is highest in the sky.

[8] In modern times, the gegenschein is not visible in most inhabited regions of the world due to light pollution.