By“dark side”I think you mean the side we never see from earth．We see only one side of the moon because of the moon's special movem ent．It is moving in such a way that it takes the same length of time for each once-around spin（自转）and for each trip around the earth．
The neat result is that it always keeps the same face toward the earth．And it also has a side that always faces away from the earth— which people sometimes call the“dark side”，even though it gets plenty of sunlight．
Russian and U．S．spaceships have photographed all of the moon's surface．But it seems that there has been no particular reason（特殊的原因）to actually visit the“other”side．Maybe that will become a site（地点） of exploration（探险）in your generation（代）．（from Highlights for Children）
