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The Gegenschein Picture of a rare phenomenon The gegenschein is a german word meaning "counterglow". It was discovered in 1854 by the Danish astronomer Theodor Brorsen. This is a very faint brightening visible at night in the anti-solar zodiacal region (thus over the eastern horizon at night and over the western horizon in the morning). This phenomenon is associated to the zodiacal light. Its existence is thus also due to dust particles that lie in the plane of the solar system and reflecting the sunlight. The gegenschein appears as a very light and elongated region extending over 10-15° in length and a few degrees wide along the plan of the ecliptic. It is fainter than the zodiacal light, and requests a night without moon neither aurora or light pollution. Even the presence of the Milky Way on which it could superimpose prevent its observation.
Like the zodiacal light and aurora, its recording requests a fast film (400 ISO) and the use of a wide angle lens (8-35 mm). The best location to observe it are deserts, high altitude sites (in ranges over 2000m) and sometimes at sea (La Réunion, Taipan, etc). Some more images Manchester Astronomical Society
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