People have always seemed to believe the moon was controlling their lives. In the past, they used it as a calendar and planted their crops according to the phases of the moon. Now people know it moves the tides in the oceans and affects how fast the earth turns. It may have once been a part of our world. Journeys to the moon by astronauts have given astronomers many answers to questions about our special satellite, but there are many more things they want to know.