Starwatch: Libra is visible all evening but wait until midnight to do it justice

This week you can track down one of the fainter zodiacal constellations. Libra, the scales, is located in the southern celestial hemisphere, and so never rises that high in northern skies, but it is most visible from the northern hemisphere at this time of year.

The chart shows the view looking south-west at midnight tonight. Although Libra will be visible all evening, it is worth waiting until midnight to see it in the correct context. It sits between the zodiacal constellations of Virgo, the virgin, to the west and Scorpius, the scorpion, to the east.

A number of ancient cultures used to think of Libra as an extension of Scorpius. They saw it as the scorpion’s claws and indeed the Arabic star names of Zubeneschamali and Zubenelgenubi II mean northern claw and southern claw respectively. Simultaneously, the constellation was also associated with balance and justice, hence its enduring depiction as a set of scales.

Zodiacal constellations are so called because the sun passes through their patch of sky at certain times of the year. For Libra, the sun is within its boundaries between 30 October and 23 November every year. From Sydney, Australia, look for the constellation in the western sky during the evening.