Why do we always see the same side of the moon?

We always see the same side of the moon because the moon rotates once on its axis during the time it completes one revolution around the Earth-which is 27 days, 7 hours, and 43 minutes. The mutual attraction between the Earth and the moon has tuned these two movements in this way. In fact, we did not know for a long time how the moon looked 'from behind'. In 1959, a Russian probe send pictures of the unseen side of the moon to the Earth. The Apollo spaceship landed on the visible side of the moon because a radio connection could not be established with the other side.