There is no permanent dark side of the Moon. Both the side facing Earth (near side) and the side facing away (far side) receive sunlight equally over the course of a lunar day, which lasts about 29.5 Earth days. The phrase "dark side of the Moon" is misleading and often refers to the far side, which was historically unknown and unexplored rather than literally dark. The Moon is tidally locked to Earth, meaning the same side always faces Earth, but both sides get sunlight during their lunar day and night cycles. The far side is sometimes called "dark" because it is out of direct radio contact when spacecraft orbit there, and it was largely unknown before space missions could observe it.
