What is the difference between a zodiacal sign and a constellation?

Zodiacal signs are 30 degree sectors of an imaginary circle drawn in the sky called the Ecliptic. They are named for astronomical constellations, but do not tally or match up with them since astrology and astronomy parted company long ago. There are other astronomocal constellations - groups of stars, which are outside the Ecliptic and not referred to or meaningful for astrologers.



In an astrological chart, an astrologer sometimes refers to a group of planets connected by certain aspects - 30, 60, 90, 120 180 degrees for example, as a constellation, and will interpret a chart according to how they see the planets and aspects combining.



Geddit?What is the difference between a zodiacal sign and a constellation?The 13 Constellations of the Zodiac



The Zodiac is the ring of constellations that the Sun seems to pass through each year as the Earth orbits around it. Contrary to popular belief, there are actually 13 zodiacal constellations, if you pay attention to the way astronomers define them. In addition to

Capricornus, Aquarius, Pisces, Aries,

Taurus, Gemini, Cancer, Leo,

Virgo, Libra, Scorpius, and Sagittarius,

the Sun also passes through

Ophiuchus.

Try getting some astrologer to explain THAT one to you...



While you're at it, ask them to explain why all the "Signs of the Zodiac" are off by about one month. (hint: astrology was invented more than 2000 years ago and the precession of the Earth's pole has caused changes in the postions of the stars since then)



The path the Sun follows is called the ecliptic. The ecliptic plane is the plane defined by the Earth's orbit around the Sun. All of the planets except Pluto orbit very near the ecliptic plane, so you will usually find all of them in zodiacal constellations.



Notice that in astronomy, it is Scorpius, not Scorpio and Capricornus, not Capricorn. These are the official names for the constellations.