Yōga Sūtra 3.28

चन्द्रे ताराव्यूहज्ञानम्।

candrē tārāvyūhajñānam।

[चन्द्रे तारा व्यूह ज्ञानम्।
candrē = the moon; tārā = star; vyūha = system; jñānam = knowledge;]

By (samyama on) the moon one gains the knowledge of star systems.