In Western astrology, astrological signs are the twelve 30º sectors of the ecliptic, starting at the vernal equinox (one of the intersections of the ecliptic with the celestial equator), also known as the First Point of Aries. The order of the astrological signs is Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius and Pisces.
The concept of the zodiac originated in Babylonian astrology, and was later influenced by Hellenistic culture. According to astrology, celestial phenomena relate to human activity on the principle of "as above, so below", so that the signs are held to represent characteristic modes of expression, or primary energy patterns indicating specific qualities of experience, through which planets manifest their dimension of experience.
The Age of Aquarius is an astrological term denoting either the current or upcoming astrological age, depending on the method of calculation. Astrologers maintain that an astrological age is a product of the earth's slow precessional rotation and lasts for 2,150 years, on average. In popular culture in the United States, the Age of Aquarius refers to the advent of the New Age movement in the 1960s and 1970s.
There are various methods of calculating the length of an astrological age. In sun-sign astrology, the first sign is Aries, followed by Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, and Pisces, whereupon the cycle returns to Aries and through the zodiacal signs again. Astrological ages, however, proceed in the opposite direction ("retrograde" in astronomy). Therefore, the Age of Aquarius follows the Age of Pisces.