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    Re: Raw data for bubble
    From: Bill B
    Date: 2007 Mar 21, 16:22 -0400

    > From: "Bill Noyce" 
    > I'll take a shot at answering some of Bill's questions...
    > The "magic number" 0.2724 isn't an angle, it's simply the ratio
    > moon_radius / earth_radius
    > SD is the angular distance of the moon's radius as seen from the
    > earth, and similarly HP=SD/0.2724 is the angular distance of the
    > earth's radius as seen from the moon, which is another way of
    > describing the parallax of the moon at the horizon.  When we're on the
    > line from the center of the earth to the moon, parallax is zero (and
    > Ho=90 degrees).  For intermediate cases, cos(Ho) represents how far
    > from that centerline we are, and thus how much of the HP to include.
    Thank you Bill.  I guess what mislead me was the N.A. presentation of the
    0.2724 constant which is does present as an decimal degrees. I am still
    pondering it.
    Bill N.
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