Question

Why is there a difference in the moon rotation time period , 27days -29 days?

Answer 1

The orbital period and rotation rate of the moon, which istidally lockedso that the same side always faces the earth (there is a teensy bit of wobble to this) are the same at 27.322 days (in “proper” decimal notation). see your ans for 29 29.53 days. The moon rotates once every 27 days 7 hours and 43 minutes 12 seconds (27.32 days). But like the earth, it goes around the sun every 365.26 days. That means it rotates 365.26/27.32, or 13.37, times each trip around the sun. However, because it is going around the sun, it only experiences 12.37 sunrises in that trip. So the length of a day on the moon is about 365.26/12.37, or 29.53, days.