In a satellite of our Earth has one property, which we'll talk about today. The fact is that the orbit of the moon is not quite right — that is not circular. In lunar orbit is a slight deviation — eccentricity. In this regard, it is periodically Moon plots farthest from the Earth, the closest (apogee and perigee).
Close to the most remote parts of the angular velocity of the moon relative to the planet is less, while the rotation speed is the same (as you know, a lunar month is approximately equal to the lunar day). Near the closest to Earth areas of the lunar orbit opposite situation. As a result the Moon relative to the Earth and then it turns a little on one side, then the other. This leads to the fact that the Earth can be considered half the moon's surface, and about 59% (western and eastern edge of the back side of the moon).
Libration in longitudehas an amplitude of about 7 ° 54?, it is connected with the fact that the orbit of the Moon around the Earth is not circular. For this reason, the speed of the moon in its orbit is unstable, while its rotation around its axis is at an almost constant rate. As a result, the apparent rotation of the earth observer Moon uneven, and the viewer can turn a little "look" in turn from the earth turn from the eastern hemisphere and the western edge. The period of libration in longitude — anomalistic month.
Libration in latitudehas an amplitude of about 6 ° 50?, it is due to the inclination of the axis of rotation of the Moon to the plane of its orbit around the Earth. At movement of the moon around the earth we see the south, the north pole of the moon. The period of libration in latitude — draconic month.
Data — Wikipedia / Astronomy.
Now let us turn to the video at the beginning of the article. It was made in March 2012, a month is compressed to 12 seconds. We will take pictures of the video, which shows the extreme positions of the moon (when the moon turned to us that the eastern boundary, then west). We define the slope with some simple changes, and compare with the above data.
Even if the resulting angle divided by 2, it would still be much greater than the encyclopedic data. That is, the lunar libration — something casual, or satellite of the Earth is something wrong … Who has any opinions?