A faint light covering a 20-degree field-of-view projected on the celestial sphere about the Sun-Earth vector (as viewed from the dark side of the Earth).
Germanic version of counterglow.
Brightening of the zodiacal light in the direction opposite the Sun.
A faint light observed from the dark side of the Earth in a direction opposite to the Sun. It results from sunlight reflected by dust particles which orbit the Sun at planetary distances.
A round or slightly elongated area of light seen in the night sky along the zodiac. Like the zodiacal light, the gegenschein is mainly sunlight scattered by particles in interplanetary space along the ecliptic. The zodiacal light is forward scattered while the gegenschein is backscattered light.
Gegenschein is also known as the counterglow. It is a faint oval patch of light that is very difficult to see, you need a clear and moonless night. It is at the antisolar point i.e. exactly opposite the Sun. It is apparently best seen when the ecliptic is at its highest above the horizon (midwinter from the northern hemisphere and vice versa for the southern hemisphere). It is not well understood but is thought to be caused by the scattering of sunlight from dust in the main plane of the Solar System. Sometimes it can be seen to be joined to the zodiacal light by a parallel sided beam of light. I think that this beam is called the zodiacal band but cannot be 100% sure. I also believe that it is larger in the tropics than in the temperate zones. Click here to visit the NASA website and view a picture of the gegenschein.
Gegenschein (German for counterglow, pronounced gey-guhn-shahyn), is a faint brightening of the night sky in the region of the ecliptic directly opposite the Sun. It was discovered in 1854 by the Danish astronomer Theodor Brorsen.