Location of photoCimarron Co., Oklahoma, USA
Date/Time of photoMidnight on Oct. 21, 2001
EquipmentThis is a 30 minute exposure with an all-sky camera, a 16mm lens @ f/4 on a Mamiya back, loaded with Fuji Provia 400F pushed to ISO 800. The foreground was illuminated with a red-filtered electronic flash and a red flashlight.
DescriptionFramed by the Miky Way and airglow, the Gegenschein - subtle sentinel of the midnight meridian - floats like a vapor above the 2001 Okie-Tex Star Party.
The Gegenschein, German for counterglow, is caused by sunlight reflecting off of dust in the ecliptic plane. It is always exactly 180 degrees from the sun, and is actually an enlarged and brighter portion of the zodiacal band which can be seen from very dark skies when airglow is at a minimum. The dust particles are fully lit at opposition, and that is why the zodiacal band is brighter and larger.
The zodiacal light is part of the same overall phenomenon, and best seen near the sun in either the evening or morning during the spring and fall respectively in the northern hemisphere, and is the brightest due to solar proximity.
The above is copyrighted Doug Zubenel.