The earth has a mass, me, of approximately 6 x 1024 kg. we will assume the moon has a mass, mm, of only about 1.2% that of earth (you may use 7.3 x 1022 kg) and a rotational period, t, around the earth of 28 days (or about 2.4 x 106 secs). finally the eccentricity, e, of the moon’s orbit is 0.055.