Suppose that a future astronaut base on the moon will need to be able to communicate with the earth at any time. in order to be able to communicate, the lunar base must be designed so that it is in constant "line of sight" contact with the earth so that radio signals can be sent back and forth. this means that a) the lunar based must be placed on the far side of the moon on the dark side of the moon. b) it is impossible that the earth can always be seen from any one place on the moon. c) on the near side of the moon.