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    Re: Lunar mechanics and Double Alts.
    From: George Huxtable
    Date: 2003 Apr 30, 23:11 +0100

    Can I backtrack a bit, please?
    In reply to a posting from Fred Hebard, I wrote earlier-
    >Other navigational planets will also be near the plane of the ecliptic:
    >Venus can't get >more than 8 deg away, Mars, Jupiter, and Saturn closer
    >still. So it can be assumed that >these bodies, like the Sun and Regulus,
    >are always suitable candidates for a lunar >distance, as long as the lunar
    >distance exceeds 20 deg or so.
    I have had second thoughts about that, particularly as it applies to Venus.
    In the worst case, Venus could be 8 deg one side of the ecliptic, and the
    Moon could be 5 deg the other side. So as the Moon passes Venus in the sky,
    it's possible for them to be 13 deg apart. In that case, a minimum lunar
    distance of 20 deg, as I suggested, wouldn't really be enough to ensure
    that the Moon and Venus were closing at anywhere near the full possible
    rate. It would need a minimum lunar distance of 40 deg, instead.
    contact George Huxtable by email at george@huxtable.u-net.com, by phone at
    01865 820222 (from outside UK, +44 1865 820222), or by mail at 1 Sandy
    Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.

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