The period of the moon’s orbit about the Earth is 27.3 days, but the average time between full moons is approximately 29.3 days. The difference is due to the motion of the Earth about the sun.
a. Through what fraction of its total orbital period does the Earth move in one period of the moon’s orbit?
b. Draw a sketch of the sun, the Earth, and the moon with the moon in the full moon condition. Then, 27.3 days later sketch the moon’s position again for the new position of the Earth. If the moon is in the same position relative to Earth as it was 27.3 days earlier, is this a full moon?
c. How much farther would the moon have to go to reach the full moon condition? Show that this represents approximately an extra two days.