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It takes the Moon about 27 days to go around the Earth once. If you check on the Moon several times during one night, you will notice that it moves relative to the stars around it. As the Moon goes around the Earth, different portions of it are lit up by the Sun, causing lunar phases. It takes the Moon one month to go through all its phases.
Have you ever heard the term the 'far-side' of the Moon? The Earth's
gravity produces tidal
forces on the Moon. This causes the same side of the moon to
always face the Earth. People living on the Earth can never see the
'far-side' of the Moon, unless they go there! Tidal forces cause many
of the moons of our solar system to always face their planets.
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It takes the Moon 27.322 days to go around the Earth once. Because of this motion, the Moon appears to move about 13° against the stars each day, or about one-half degree per hour. If you watch the Moon over the course of several hours one night, you will notice that its position among the stars will change by a few degrees. The changing position of the Moon with respect to the Sun leads to lunar phases.
Have you ever heard the term the 'far-side' of the Moon? Because of
the effect on the Moon of tidal
forces due to the Earth, the same side of the moon always faces
the Earth. In other words, it takes the Moon the same amount of time
to rotate around once as it does for the Moon to go around the
Earth once. Therefore, Earth-bound observers can never see the
'far-side' of the Moon. Tidal forces cause many of the moons of our
solar system to have this type of orbit.
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The Moon's orbital period is 27.322 days. Because of this motion, the Moon appears to move about 13° against the stars each day, or about half of a degree per hour. If you watch the Moon over the course of several hours one night, you will notice that its position among the stars will change by a few degrees. The changing position of the Moon with respect to the Sun leads to lunar phases.
Have you ever heard the term the 'far-side' of the Moon? Because of
the effect on the Moon of tidal
forces due to the Earth, the same side of the moon always faces
the Earth. The rotation period and the orbital period of the Moon are
the same. Therefore, Earth-bound observers can never see the
'far-side' of the Moon. Tidal forces cause many of the moons of our
solar system to have this type of orbit.
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Last modified prior to September, 2000 by the Windows Team
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