has a local origin in the inner Solar System, best fitting the planet Mars as a source. Appearance Zodiacal light is produced by sunlight reflecting off dust particles in the Solar System known as cosmic dust. Consequently, its spectrum is the same as the solar spectrum. The material producing the zodiacal light is located in a lens-shaped volume of space centered on the sun and extending well out beyond the orbit of Earth. This material is known as the interplanetary dust cloud. Since most of the material is located near the plane of the Solar System, the zodiacal light is seen along the ecliptic. The amount of material needed to produce the observed zodiacal light is quite small. If it were in the form of 1 mm particles, each with the same albedo (reflecting power) as Earth's moon, each particle would be 8 km from its neighbors. The gegenschein may be caused by particles directly opposite the Sun as seen from Earth, which would be in full phase. According to Nesvorný and Jenniskens, when the dust grains are as small as about 150 micrometres in size, they will hit the Earth at an average speed of 14.5 km/s, many as slowly as 12 km/s. If so, they pointed out, this comet dust can survive entry in partially molten form, accounting for the unusual attributes of the micrometeorites collected in Antarctica, which do not resemble the larger meteorites known to originate from asteroids. In recent years, observations by a variety of spacecraft have shown significant structure in the zodiacal light including dust bands associated with debris from particular asteroid families and several cometary trails. Cultural significance According to Alexander von Humboldt's Kosmos, Mesoamericans were aware of the zodiacal light before 1500. It was perhaps first reported in print by Joshua Childrey in 1661. The phenomenon was investigated by the astronomer Giovanni Domenico Cassini in 1683. According to some sources, he explained it by dust particles around the Sun. Other sources state that it was first explained this way by Nicolas Fatio de Duillier, in 1684, whom Cassini advised to study the zodiacal light. Importance to Islam The Islamic prophet Muhammad described zodiacal light in reference to the timing of the five daily prayers, calling it the "false dawn" ( ). Muslim oral tradition preserves numerous sayings, or hadith, in which Muhammad describes the difference between the light of false dawn, appearing