Venus rotates in the opposite direction to most planets, a phenomenon known as retrograde rotation. The reason for this unusual rotation is not completely understood, but several theories exist. One prominent theory suggests that a massive collision with a large object early in its history could have reversed Venus's rotation. Another theory proposes that gravitational interactions and tidal effects from the Sun could have slowed down its original prograde rotation and eventually reversed it. This retrograde rotation is one of Venus's many unique and intriguing characteristics, setting it apart from most other planets in the solar system.