From saṃyama on the moon arises knowledge of the arrangement of the stars.

Candra is the moon. Tārā are the stars. Vyūha is arrangement, formation.

The moon represents the mind (manas) and the reflective principle. By meditating upon it, the yogī comes to know the stellar order.

While the sun gives knowledge of the vertical worlds (planes of existence), the moon gives knowledge of horizontal space (the arrangement of celestial bodies).

This includes not only positions but movements, cycles, influences. It is the basis of jyotiṣa, Vedic astrology.

The moon also represents the receptive, the intuitive, the nocturnal. Saṃyama upon it develops cosmic intuition.

In tantric practice, the moon is visualized at the center of the head, pouring nectar. This saṃyama has both cognitive and physiological effects.

The ancient ṛṣis who codified the Vedas supposedly used these methods for their astronomical knowledge.