zodiacal light

zodiacal light or zodiacal band, a faint band of light sometimes seen in the western sky just after sunset in the spring, extending up from the horizon at the point where the sun has just set, or in the eastern sky just before sunrise in the autumn. The light is so faint as to be obscured by moonlight. It is caused by the reflection and scattering of sunlight by a sparse band of tiny dust particles that appears to be an extension of the solar corona, stretching out beyond the orbit of Jupiter. Concentrated in the plane of the ecliptic, the faint light is best seen in the region of the sky called the zodiac. Near the equator the zodiacal light sometimes seems to stretch completely across the sky. It was first investigated and explained by the astronomer Gian Domenico Cassini about 1690.

See also gegenschein.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.

More on zodiacal light from Fact Monster:

See more Encyclopedia articles on: Astronomy: General