Friday, 1 October 2010

zodiacal light - the false dawn

Thanks to Jane for sharing this. In thinking about the faint amount of light that allows you to discern form in the darkness in my previous post depicting the night-time profiles of mountains, this phenomena  seems an interesting addition.

"Zodiacal light is a faint, roughly triangular, whitish glow seen in the night sky which appears to extend up from the vicinity of the sun along the ecliptic or zodiac. Caused by sunlight scattered by space dust in the zodiacal cloud, it is so faint that either moonlight or light pollution renders it invisible. The zodiacal light decreases in intensity with distance from the Sun, but on very dark nights it has been observed in a band completely around the ecliptic. In fact, the zodiacal light covers the entire sky, being responsible for 60% of the total skylight on a moonless night. There is also a very faint, but still slightly increased, oval glow directly opposite the Sun which is known as the gegenschein." (Wikipedia)

Zodiakallicht - Etienne Leopold Trouvelot

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