The zodiacal constellation Libra the Scales is a fixture of the evening sky during a Northern Hemisphere summer (Southern Hemisphere winter). It’s not the most flamboyant constellation of the zodiac. But, in any year, you can find Libra fairly easily in a dark sky using two bright stars, Spica and Antares, as guides. Use these two bright stars to find two fainter stars in Libra, which, by the way, have two of the best star names: Zubenelgenubi and Zubeneschamali.
How to find Libra
Libra is a constellation of the zodiac. Thus, you will know to look for it along the sun’s path across our sky, the ecliptic.
Two stars in Libra sit about midway between the two bright stars Spica and Antares. Those two Libra stars are Zubenelgenubi and Zubeneschamali, and they mark Libra’s place in the heavens.
Libra and the ecliptic
As seen from Earth, the sun passes in front of the constellation Libra from about October 30 until November 22 every year.
Libra’s star Zubenelgenubi sits almost exactly on the ecliptic, which is the sun’s yearly path in front of the background stars. At present, the sun has its annual conjunction with Zubenelgenubi on or near November 7, or about midway between the September equinox and the December solstice.
However, the conjunction date of the sun and Zubenelgenubi changes over the long course of time.
More than 3,000 years ago, the sun and Zubenelgenubi were in conjunction on the Northern Hemisphere’s autumnal equinox (Southern Hemisphere’s spring equinox). Over 3,000 years into the future, the sun and Zubenelgenubi will be in conjunction on the December solstice (Northern Hemisphere’s winter solstice or Southern Hemisphere’s summer solstice).
Regardless of which constellation provides a backdrop for the sun on the September equinox, the sun is said to be at the first point of the sign Libra when it the crosses the celestial equator going from north to south.
Read more: what’s the difference between a sign and a constellation?
Libra in history and myth
Several thousand years ago – around 2,000 BCE – the ancient Babylonians apparently associated this constellation with scales or a balance. Quite possibly, they made this association because the sun on the autumnal equinox shone in front of the stars of Libra at that time. It’s at the equinox that the world realizes its seasonal and temporal balance between the extremes of heat and cold, and with day and night of equal length all over the globe. Metaphorically, Libra the Scales serves as an age-old symbol of divine justice, harmony and balance.
In contrast to their Babylonian forebears, the ancient Greeks seemed to regard Libra as the outstretched claws of the constellation Scorpius the Scorpion. In fact, the names for Libra’s two brightest stars are Arabic terms that hearken back to these olden times when Scorpius reigned as a double or super constellation. Zubenelgenubi translates into the southern claw of the Scorpion and Zubeneschamali into the northern claw of the Scorpion.
The Romans, though inheriting much of the Greek tradition, again revived Libra as the only inanimate constellation of the zodiac. In Roman thought, the constellation Virgo is the embodiment of Astraea, the Starry Goddess, holding Libra, the Scales of Justice.
Astrologers regard Libra as the second air sign, ruled over by the planet Venus. Although astronomy and astrology have been intertwined historically, they are now regarded as separate disciplines. Astrology assumes the positions of heavenly bodies have certain influences over human affairs which most modern-day astronomers regard as unfounded.
More constellations of the zodiac
Meet Taurus the Bull in the evening sky
Meet Gemini the Twins, home to 2 bright stars
Meet Cancer the Crab and its Beehive Cluster
Leo the Lion and its backward question mark
Virgo the Maiden in northern spring skies
Meet Libra the Scales, a zodiacal constellation
Scorpius? Here’s your contellation
Sagittarius? Here’s your constellation
Capricornus the Sea-goat has an arrowhead shape
Aquarius? Here’s your constellation
Meet Pisces the Fish, 1st constellation of the zodiac
Say hello to Aries the Ram
Born under the sign of Ophiuchus?
Bottom line: Find the zodiacal constellation Libra the Scales in the evening sky during Northern Hemisphere summer (Southern Hemisphere winter) between two bright stars, Spica and Antares.
The post Meet Libra the Scales, a zodiacal constellation first appeared on EarthSky.
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