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    Re: Refraction and the Moon (near horizon)
    From: Frank Reed CT
    Date: 2005 Aug 27, 00:07 EDT

    Frank (another Frank!) wrote:
    "Each morning I  check the amazing photos offered up as APOD and
    think today's image might  interest some of you.  Check  out
    http://antwrp.gsfc.nasa.gov/apod/ap050826.html.  I recall  another
    similar image was posted recently of the moon which may be
    located  in the APOD archives."
    Nice photo, and yes, very topical...
    The  caption attributes the irregularities in the Moon's appearance to the
    "turbulent  atmosphere". Well, sort of. The notches and bumps in the Moon's limb
    are  basically symmetric (notice the notches in the limb at 4 and 8 o'clock
    and the  bumps at 10 and 2) and they are caused by relatively stable,
    non-turbulent  patterns in the density profile of the lower atmosphere. Except for the
    fact  that the entire lower atmosphere owes its properties to turbulence
    (hence the  name troposphere), this is not evidence of turbulence --it's evidence
    of  layering.
    42.0N 87.7W, or 41.4N  72.1W.

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