Question

If it takes 27.3 days for the moon to

make 1 revolution around the Earth,
why does it take a total of 29.5 days
to complete 1 set of phases?

Answer 1

It takes the moon a total of 29.5 days to complete 1 set of phase because of the Earth's revolution around the Sun.

Step-by-step explanation:

The moon is the only natural satellite of the Earth, which rotates about its axis and also revolves or orbits around the Earth. Where the Earth orbits around the Sun.

The moon completes an orbit in 27.3 days, but due to the Earth's revolution around the Sun it would take the moon 29.5 days to return to its required point which coincides with that of the Sun. Thus completing 1 set of phase.

As the moon is rotating about its axis, it orbits about the Earth and also in synchronize motion with the revolution of the Earth about the Sun.

Answer 2

Step-by-step explanation:

It takes 27.3 days for moon to make one revolution this is called sidereal month and it takes 29.5 days to complete a cycle of phase this is called synodic month. The synodic month is difference is because as the moon moves around earth, the earth is also moving round the sun. Hence, the moons needs to move farther away to make up the distance that was added as the earth also revolves in other to complete the cycle.