Movements of the Moon:
The Moon appears to orbit the earth. To an observer in outer space, however, the earth and its moon appear to orbit each other. The earth and its moon together would appear to form a single system that orbits the sun. The center of the earth-moon system, follows a smooth orbit around the sun.
The Balance point of the earth and moon system is not halfway between the centers of the two bodies, the balance point is in the interior of the earth, because of the greater mass of the earth.
The orbit of the moon around the earth forms an ellipse, not a circle. Therefore the distance between the earth and its moon varies. When the moon is farthest from the earth, it is at apogee. when the moon is closest to the earth, it is at perigee. The Average distance of the moon from the earth is 384,000 km.
The rotation of the earth on its axis causes the moon to appear to rise and set. In addition to orbiting the earth and revolving around the sun as part of the earth-moon system, the moon also spins on its axis. It spins very slowly,completing a rotation only once during each orbit around the earth. The moon makes one revolution around the earth in about 27.3 days relative to the stars. The rate of which the moon rotates is due to the effect of the earth's gravity. Because the rotation and the revolution of the moon take the same amount of time, observers on the earth always see the same side of the moon. The moon also rocks slightly on its axis. As a result, observers on the earth can see about 59 percent of the surface of the moon.
The Balance point of the earth and moon system is not halfway between the centers of the two bodies, the balance point is in the interior of the earth, because of the greater mass of the earth.
The orbit of the moon around the earth forms an ellipse, not a circle. Therefore the distance between the earth and its moon varies. When the moon is farthest from the earth, it is at apogee. when the moon is closest to the earth, it is at perigee. The Average distance of the moon from the earth is 384,000 km.
The rotation of the earth on its axis causes the moon to appear to rise and set. In addition to orbiting the earth and revolving around the sun as part of the earth-moon system, the moon also spins on its axis. It spins very slowly,completing a rotation only once during each orbit around the earth. The moon makes one revolution around the earth in about 27.3 days relative to the stars. The rate of which the moon rotates is due to the effect of the earth's gravity. Because the rotation and the revolution of the moon take the same amount of time, observers on the earth always see the same side of the moon. The moon also rocks slightly on its axis. As a result, observers on the earth can see about 59 percent of the surface of the moon.