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Moon cycles

Victor · 2004-07-07 00:05:13

Do I have it right that the time for the moon to rotate on it's axis is exactly (which seems statisticly unlikely) the same time it take to rotate around the Earth and hence we only ever see one face illuminated? Or does it just not rotate?

07-07-2004 12:05am

#1

Victor

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Do I have it right that the time for the moon to rotate on it's axis is exactly (which seems statisticly unlikely) the same time it take to rotate around the Earth and hence we only ever see one face illuminated?

Or does it just not rotate?

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Comments

#2 07-07-2004 9:12am

albertw

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Posts: 342

Hi,

Yep it has the same rotational period and orbital period.

At first glance this does seem an unlikley coincidence, but in fact its quite common among moons in the solar system. The relationship is caused by gravitational tidal forces, and the moon is said to be tidally-locked or phase-locked. Seaching for this online will bring up better explanations that I can give, but basically always having one side pointing towards the Earth is the most stable situation.

Cheers,
~Al

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