Although there are more than 12 constellations visible from earth, the most common are the zodiac constellations. These constellations were recognized and named by the Greeks thousands of years ago. The zodiac is divided into 12 sections of 30° each, which are called the signs of the zodiac. Starting with the vernal equinox and then proceeding eastward along the eclipticThe zodiac is divided into 12 sections of 30° each, which are called the signs of the zodiac. Starting with the vernal equinox and then proceeding eastward along the ecliptic. The ecliptic is the path which the sun takes. The names of the zodiacal signs are Aries, the Ram; Taurus, the Bull; Gemini, the Twins; Cancer, the Crab; Leo, the Lion; Virgo, the Virgin; Libra, the Balance; Scorpio, the Scorpion; Sagittarius, the Archer; Capricornus, the Goat; Aquarius, the Water Bearer; and Pisces, the FishesThe names of the zodiacal signs are Aries, the Ram; Taurus, the Bull; Gemini, the Twins; Cancer, the Crab; Leo, the Lion; Virgo, the Virgin; Libra, the Balance; Scorpio, the Scorpion; Sagittarius, the Archer; Capricornus, the Goat; Aquarius, the Water Bearer; and Pisces, the Fishes. Because all of the zodiacal constellations lie on the ecliptic, they can all be seen from anywhere in the world.

There are, of course, more than 12 constellations visible to the naked eye from earth. But some are only visible in the northern hemisphere, some are only visible in the southern hemisphere, and at different times of year. In the northern hemisphere, you can see the northern constellations most of the time, the middle constellations some of the time, and some of the sothern constellations cannot be seen at all. The reverse holds true in the southern lattitudes. Along the equator, all of the known constellations can be seen some of the time.

So choose which zodiacal constellation you wish to learn about and click on it to the left of your screen.