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Moon showing Libration

Pictures taken 13.5 days apart showing libration (in both dirctions) and a change in size.
The Moon’s rotation period is equal to the time for the Moon to orbit around the Earth one time, thus it always has the same side facing the Earth. There are however three major sources of Lunar Libration that allow us to see more of the Moon.
1. East- West Libration-The Moon has an elliptical orbit about the Earth, when the moon is closer to the Earth it speeds up and when it is farther away it slows down. This allows us to see a bit farther in the east-west direction.
2. North-South Libration-The Moon's orbit is tilted to the ecliptic plane and to the Earth's equator. This allows us to see a bit more in the north-south direction as the orientation changes.
3. Slight East-West-North-South Libration- The location on the Earth that the Moon is being observed from causes a slight shift in what part of the Moon is visible. If you are at the poles you get a little help in the North –South direction and if look at the Moon in the Evening vs. the morning you see a bit more in the East-West direction.

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