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Thread: Why is there no Lunar rotation?

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    Default Why is there no Lunar rotation?

    Question for ANYONE, Is there ANY orbiting moon (other than ours) around ANY other planet that does not show the back side?

    i.e. It does not spin/rotate/revolve on its axis?

    Why does our moon not spin on its axis?

    thanks in advance



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    Actually it does spin on its own axis...

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    Quote Originally Posted by cmangle View Post
    Question for ANYONE, Is there ANY orbiting moon (other than ours) around ANY other planet that does not show the back side?

    i.e. It does not spin/rotate/revolve on its axis?

    Why does our moon not spin on its axis?

    thanks in advance
    The answer I surmised in general chat...please correct me if I'm wrong...

    I dunno...interesting question. There ARE people on this board who would know the definite answer to that.

    My thoughts for what they are worth.

    A quirk in the orbit/distance/rotation of the moon at this current point in time results in its duration of rotation and its distance from the earth matching that of the duration of the earths, resulting in one only side being visible.

    If that's the case I would doubt the odds of that happening somewhere else at this same time for a rotating moon.

    Happy to be corrected.
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    From
    Does the Moon Rotate?
    By Nola Taylor Redd, Space.com Contributor | February 28, 2014 08:39pm ET



    Does the Moon Rotate?
    Miguel Claro recently sent Space.com this beautiful image of the moon and Earthshine taken from Almada, Portugal on Feb. 1, 2014. “I could see the night side of the moon very well illuminated by the Earth reflected light, like if it was full moon,” Claro wrote Space.com in an email. “This impressive phenomenon known as Earthshine, was described and drawn for the first time, by the great Leonardo Da Vinci about 500 years ago in his book Codex Leicester.”
    Credit: Miguel Claro |


    Attentive observers on Earth might notice that the moon essentially keeps the same side facing our planet as it passes through its orbit. This may lead to the question, does the moon rotate? The answer is yes, though it may seem contrary to what our eyes observe.
    The 'dark' side of the moon

    The moon orbits the Earth once every 27.322 days. It also takes approximately 27 days for the moon to rotate once on its axis. As a result, the moon does not seem to be spinning but appears to observers from Earth to be keeping almost perfectly still. Scientists call this sychronous rotation.

    The side of the moon that perpetually faces Earth is known as the near side. The opposite or "back" side is the far side. Sometimes the far side is called the dark side of the moon, but this is inaccurate. When the moon is between the Earth and the sun, during the new moon phase, the back side of the moon is bathed in daylight.

    The orbit and the rotation aren't perfectly matched, however. The moon travels around the Earth in an elliptical orbit, a slightly stretched-out circle. When the moon is closest to Earth, its rotation is slower than its journey through space, allowing observers to see an additional 8 degrees on the eastern side. When the moon is farthest, the rotation is faster, so an additional 8 degrees are visible on the western side. [The Moon: 10 Surprising Lunar Facts]

    If you could journey around to the far side of the moon as the Apollo 8 astronauts once did, you would see a very different surface from the one you are accustomed to viewing.

    For more, go to the space.com website (link above).

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    The answer you're looking for cmangle is that the moon is "Tidally locked".

    You can also demonstrate how this happens at home very easily.
    Pick something that is round and can spin on an axel. If you can't find something you can make one.
    The bigger the object is the better the example will work. I have a big 1.2m cat wheel (like a big hamster wheel) and it works very well.

    But for a quick example you can cut out a piece of wood into a circle or even a piece of cardboard.
    Drill a hole in the center and nail or pin it to a wall. Then spin it. It should spin several times before it stops.
    When the wheel stops, put a pen mark on bottom. Then spin it again.
    Where does the mark stop each time you spin it?

    Provided friction doesn't overpower gravity, the wheel will always stop with the mark at the bottom.
    In a big example, the wheel will spin and then the spinning will slow down enough until the mark can no longer pass over the top of the wheel.
    It then rotates backwards. The wheel now acts like a pendulum rocking back and forth slowly losing energy until the mark stops at the bottom.
    The reason is that the center of gravity is not in the same place as the center of revolution.

    The same thing happens with moons and planets.

    So a quick history of the moon.
    A long long loooong time ago there were two planets in orbit around the sun in close proximity to each other. We'll call these Earth and Theia.
    It doesn't end well for Theia. It crashed into the Earth with a glancing blow. The result was that the earth absorbed a lot of the material from the collision.
    The ejecta either fell back to earth. Some of it formed a ring around the earth and the largest clumps coalesced to form the moon (Luna).

    At this point in time the earth is spinning much faster. A day is only about 6-8 hours long.
    The moon is also spinning as the remaining material from the rings fall onto it.

    Time is now about 4 billion years ago. All we have left is the moon in a much lower orbit spinning faster. The earth also spinning faster.
    As time goes by, the tidal influence of the moon on the Earth causes the Earth's spin to slow down. This energy isn't lost, it has to go somewhere.
    It goes to the moon, who's orbit gets faster (and higher). Yes, the moon is falling up! This is still happening today.

    The moon has influence on the earth, but the earth also influences the moon. In exactly the same way as the spinning wheel.
    The moon rotating on it's own axis slowly loses some of that energy to tidal influence on the Earth. This slows down the rotation of the moon.
    Eventually, just like the wheel it stops rotating and becomes a pendulum. As time passes that rocking motion loses more energy (logrithmically) to the Earth and eventually it stops. It is now tidally locked. The same face points at the host object.

    This is the now case. But the pendulum effect is still happening, this is why you see in Tristen's post/video of the moon it is still rocking just a bit to this day.


    So which other moons are tidally locked?
    Pluto's Moon Charon is the best example.
    I'm not sure of other moons in the solar system, but I would guess that the Galilean moons of Jupiter would be tidally locked.

    It is suspected that the planet Proxima Centauri B is tidally locked to it's host star.
    And it is possible for stars to be tidally locked, particularly if they are contact binaries.
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    Of course, trash, this may well be true, but, as we weren't around back then, all we can do is guess what happened. Based on current observations this may be true, however, it is purely conjecture. It may well be the result of an advanced civilisation running out of space on what we call planet earth, setting up an orbital space "station" that we call "the Moon" and then they all just died out from overpopulation. Given the time periods that they suggest, all of their "evidence of existence" may well have just returned to dust. "Ashes to ashes, dust to dust" to quoin a phrase.
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    Hehehe ..... I have one or two friends who like listening and watching bullshit like "ancient aliens". They don't believe the bullshit, it's just entertainment to them.
    But they also like throw me a bone now and then just to see how badly I shred it. The kind of thing you post above is the stuff they like to try on me.

    Problem is, the advanced civilisation did a fantastic job of clawing it's way to the top of the food chain and then onto advanced civilisation and vanishing from history without leaving a trace.
    All of it's evolution, ancestors, stone age, metal ages, technological ages, and it's waste completely erased as if they never existed. Even the myth of Atlantis has the chance of just being embellished and mistaken identity.

    Heheh... Tidal locking. It's just too simple and rather boring compared to the exciting fictional adventures of Stargate team SG1.

    Last edited by trash; 05-06-17 at 09:11 PM.
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    Speaking of Ancient Aliens, If you want a good laugh, look up a show called "Australiens" on netflix. These blokes seriously think that the Aliens are watching them and disguise themselves as Stars! I'm bloody glad I wasn't drinking anything when that statement was made.
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    Probably the same guys who hunt Yowies.
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    The Dark side of the Moon . . .
    Last edited by cmangle; 06-06-17 at 01:40 AM.

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    After watching that video, cmangle, I know why the moon men stopped the rotation, they were all getting dizzy!
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