The moon has a rich symbolic significance in yoga mythology. In hatha yoga, for example, the sun and the moon represent the two polar energies of the human body. In fact, the word hatha itself is often divided into its two constituent syllables, “ha” and “tha”, which are then esoterically interpreted as signifying the solar and lunar energies respectively.

(are-dah chan-DRAHS-anna)
ardha = half
candra = glittering, shining, having the brilliancy or hue of light (said of the gods); usually translated as “moon”
Half Moon Pose: Step-by-Step Instructions

Perform Utthita Trikonasana to the right side, with your left hand resting on the left hip. Inhale, bend your right knee, and slide your left foot about 6 to 12 inches forward along the floor. At the same time, reach your right hand forward, beyond the little-toe side of the right foot, at least 12 inches.

Pose of the Week: Half Moon Pose

Exhale, press your right hand and right heel firmly into the floor, and straighten your right leg, simultaneously lifting the left leg parallel (or a little above parallel) to the floor. Extend actively through the left heel to keep the raised leg strong. Be careful not to lock (and so hyperextend) the standing knee: make sure the kneecap is aligned straight forward and isn’t turned inward.

Rotate your upper torso to the left, but keep the left hip moving slightly forward. Most beginners should keep the left hand on the left hip and the head in a neutral position, gazing forward.