There is virtually no “best time” to launch a rocket to the moon, because, in terms of space travel, the journey is so short. The average distance is 238,000 miles, with a maximum variation of only 25,000 miles. A space shot, whether to the moon or some other object, is made by a rocket already in orbit. To take a rocket out of orbit and put it on course for the moon calls for boost in speed to 25,000 miles (40,000 kilometers) an hour.
This is necessary to overcome the pull of the earth’s gravity. The moment when the engines are refired to start the rocket on its journey does not depend on the position of the launching base in relation to the rocket or the moon. In contrast, the great variations in the distances between the earth and Mars or Venus make the launching of a rocket to the planets impractical for periods of nine to eighteen months.