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Vibrating moon

  1. Feb 22, 2007 #1
    If something hit the Earth billions of years ago and caused a molten blob to be released from it,and this blob settled into a spherical shape,after vibrating a lot,could the moon still be vibrating because of a formation process like this?
  2. jcsd
  3. Feb 22, 2007 #2


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    Staff: Mentor

    I guess it could, but I don't think it is. The moon is tidally locked to the earth, which probably damped-out all of that. The moon does oscillate back and forth (librations), but those are due to the eccentricity of its orbit.
  4. Feb 22, 2007 #3
    Even if completely isolated in space, it seems unlikely such a large coherent vibration would last long before being distributed among other degrees of freedom and ultimately just radiated as heat. Much like the polhode motion of a GP-B gyro.
  5. Feb 24, 2007 #4
    Layman's terms: The earth absorbs some of the vibrations of the moon, anf the moon is stabilized.
  6. Feb 24, 2007 #5


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    The reason I was interested in this thread is because there was some information received during the moon walks and experiments that suggested the moon is hollow. The pings, or whatever method discovered this phenomenon, showed reverberation taking place in the moon's interior reaches.

    Was the reverberation incorrectly diagnosed or is the moon actually hollow?
    (death star?:devil: )

    Some more legit and less legit (majority) references:


    http://forum.physorg.com/index.php?showtopic=2410 [Broken]

    Bad Astronomy: (debunks the idea)


    This one's right out there:


    This one asks "Is the moon hollow or made of swiss cheese"


    Here's where the idea may have come from...

    "...when the Apollo 13 mission dropped a tank (fuel or oxygen?) on the Moon a seismometer showed that the Moon vibrated for over 3 hours."

    http://bigbangblasted.mywowbb.com/forum1/8.html [Broken]

    This could go on indefinitely so I'll stop now.
    Last edited by a moderator: May 2, 2017
  7. Feb 26, 2007 #6
    Thanks for the list baywax. I'll check them out sooner or later.
  8. Feb 26, 2007 #7


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    Staff: Mentor

    Baywax, it should not be difficult to judge from the credibility of the sources you listed that the correct answer is that the moon is not hollow.

    Nothing about the fact that vibrations were detected when a tank was dropped suggests the moon is hollow. IIRC, the earth reverberated for weeks after that tsunami last year.
  9. Feb 27, 2007 #8


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    Thanks Russ. That probably solves the misconception, myth and waste of energy that's been put into this story.
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