Capricornus is one of the constellations of the zodiac. It is commonly called Capricorn, especially in astrology. It represents a horned goat, which is frequently called the sea goat. Capricornus is one of the 88 modern constellations and one of the 48 constellations listed by Ptolemy. Under its current boundaries, it is bordered by Aquila, Sagittarius, Microscopium, Piscis Austrinus, and Aquarius.
Depictions of a goat or goat-fish have been found on Babylonian tablets dating back three thousand years. The constellation may owe its antiquity to the fact that, at that time, the northern hemisphere's Winter Solstice occurred while the sun was in Capricorn. The concern for the sun's rebirth might have rendered astronomical and astrological observation of this region of space very important. For the same reason, the sun's most southerly position, attained at the northern hemisphere's winter solstice, is called the Tropic of Capricorn. This term also applies to the line on earth where the sun is directly overhead at noon on that solstice.
This constellation is sometimes identified as Amalthea, the goat that suckled the infant Zeus after his mother Rhea saved him from being devoured by his father Cronos in Greek mythology. The goat's broken horn was transformed into the cornucopia or horn of plenty. Some ancient sources claim that this derives from the sun "taking nourishment" while in the constellation, preparing for its northward climb. However, the constellation is often depicted as a sea goat, a goat with a fish's tail.
The astrological sign Capricorn (December 22-January 19) is associated with the constellation. In some cosmologies, Capricorn is associated with the classical element Earth and is thus called an Earth Sign (with Taurus and Virgo). Its polar opposite is Cancer, and Capricorn is a Cardinal Earth sign. Planets in Capricorn become more practical and methodical and motivated to manifest something tangible.
The keywords for Capricorn are "I USE."