Patanjali Yoga Sutra — चन्द्रे ताराव्यूहज्ञानम् ॥3.28॥

candre tārāvyūhajñānam॥

Through saṁyama on the moon, the yogi gets knowledge of different constellations of stars.

Vyāsa Maharṣi in his Pātañjala Yogasūtra Bhāṣya says — चन्द्रे संयमं कृत्वा ताराणां व्यूहं विजानीयात्॥ — i.e., by the practice of saṁyama on the moon, knowledge of constellation is obtained. Moon is the brightest celestial body at night and adhipati (Lord or Master) of tārāvyūha (constellation of stars). Hence, by saṁyama on the Moon yogi gets the knowledge of the constellation of stars.