Synchronous rotation occurs because the Moon’s rotation period matches its orbit around Earth. Tidal locking ensures one hemisphere faces Earth permanently. The far side remained hidden until spacecraft exploration. This is due to gravitational torques over billions of years. Synchronous rotation affects temperature distribution and space mission planning.
It matters for exploration because far side missions need special communication relay. Knowledge of rotation informs mapping and landing accuracy.
It also explains the permanent lunar “dark side” in human perception. It’s not always dark, just hidden from us.
The Moon rotates once every 27.3 days, matching its orbital period.
NASA [nasa.gov]