Why is there a difference between the time it takes for the Moon to orbit the Earth and the length of the lunar month?

Lunar periods It is about 27.32 days. The synodic period is longer than the sidereal period because the Earth-Moon system moves in its orbit around the Sun in each sidereal month, and therefore a longer period is required to achieve a similar alignment of the Earth, Sun and Moon.

How long does it take the moon to complete the cycle?

29.5 days
The moon takes 27.3 days to orbit the Earth, but the moon's phase cycle (from new moon to new moon) is 29.5 days. The Moon takes the extra 2.2 days to "catch up" because the Earth travels about 45 million miles around the Sun during the time the Moon completes one orbit around the Earth.

How long does it take for the Moon to orbit the Earth?

The time it takes the Moon to complete one orbit around the Earth is called a sidereal month. Sidereal refers to the Latin word for stars and sidereal month means the Moon returns to the same point under the stars. This takes an average of 27.3 days. If the Earth stood still, the synodic (lunar) month would be the same as the sidereal month.

How is a lunar month different from a lunar month?

A lunar month is the time it takes the Moon to pass through all the lunar phases, measured from one new moon to the next new moon. A lunar month includes all the phases of the moon. A lunar month is also known as a lunation, while the astronomical term for this period is a synodic month, from the Greek term synodos, meaning meeting or conjunction.

Why does the Moon take 29.5 days to return to the same point?

The Moon takes 29.5 days to return to the same point on the celestial sphere as referenced to the Sun due to the Earth's motion around the Sun (synodic month). Moon phases as observed from Earth are correlated with the synodic month.

Why does the moon rotate faster than the earth?

Because the Earth rotates faster (once every 24 hours) than the Moon orbits (once every 27.3 days), the bulge tries to "speed up" the Moon, pulling it forward in its orbit. The Moon also pulls back on Earth's tidal bulge, slowing Earth's rotation.