Zodiac Wallpaper HD
In both astrology and historical astronomy the zodiac (greek ??d?a???, zoidiakos) is a circle of twelve 30° divisions of celestial longitude that are centered upon the ecliptic: the apparent path of the sun across the celestial sphere over the course of the year. The paths of the Moon and visible planets also remain close to the ecliptic, within the belt of the zodiac, which extends 8-9° north or south of the ecliptic, as measured in celestial latitude. Historically, these twelve divisions are called signs. Essentially, the zodiac is a celestial coordinate system, or more specifically an ecliptic coordinate system, which takes the ecliptic as the origin of latitude, and the position of the sun at vernal equinox as the origin of longitude.
It is known to have been in use by the Roman era, based on concepts inherited by Hellenistic astronomy from Babylonian astronomy of the Chaldean period (mid-1st millennium BC), which, in turn, derived from an earlier system of lists of stars along the ecliptic.[1] The construction of the zodiac is described in Ptolemy's Almagest (2nd century AD).
The term zodiac derives from Latin zodiacus, which in its turn comes from the Greek ??d?a??? ?????? (zoidiakos kuklos), meaning "circle of animals", derived from ??d??? (zoidion), the diminutive of ???? (zoion) "animal". The name is motivated by the fact that half of the signs of the classical Greek zodiac are represented as animals (besides two mythological hybrids).
Although the zodiac remains the basis of the ecliptic coordinate system in use in astronomy besides the equatorial one, the term and the names of the twelve signs are today mostly associated with horoscopic astrology.
The term "zodiac" may also refer to the region of the celestial sphere encompassing the paths of the planets corresponding to the band of about eight arc degrees above and below the ecliptic. The zodiac of a given planet is the band that contains the path of that particular body; e.g., the "zodiac of the Moon" is the band of five degrees above and below the ecliptic. By extension, the "zodiac of the comets" may refer to the band encompassing most short-period comets.
The division of the ecliptic into the zodiacal signs originates in Babylonian ("Chaldean") astronomy during the first half of the 1st millennium BC, likely during Median/"Neo-Babylonian" times (7th century BC),[3] The classical zodiac is a modification of the MUL.APIN catalogue, which was compiled around 1000 BC. Some of the constellations can be traced even further back, to Bronze Age (Old Babylonian) sources, including Gemini "The Twins", from MA.TAB.BA.GAL.GAL "The Great Twins", and Cancer "The Crab", from AL.LUL "The Crayfish", among others.
The High Middle Ages saw a revival of Greco-Roman magic, first in Kabbalism and later continued in Renaissance magic. This included magical uses of the zodiac, as found, e.g., in the Sefer Raziel HaMalakh.
The zodiacal symbols are Early Modern simplifications of conventional pictorial representations of the signs, attested since Hellenistic times. The symbols are encoded in Unicode at positions U+2648 to U+2653 in the Miscellaneous Symbols block.