Welcome to the NavList Message Boards.


A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Add Images & Files
    Re: Archeological Celestial Question
    From: Paul Hirose
    Date: 2018 Jan 18, 14:44 -0800

    On 2018-01-17 12:23, Mark Coady wrote:
    > The case is that many antiquity structures are positoned to precise 
    solar/lunar/star correlations.  Favorites include stonehenge roughly 2950 BC? 
    and others aligned to summer and winter solstice events.
    >   Is there a handyonline calculator that goes that far back?  So I could 
    look at a true satellite shot with bearings vs actual angular position on 
    that date in 2950 BC? Are there any accumulated earthquake/shock events on 
    earth that might make any uniform calculator erronoeous by any signifcant 
    I forget how far back JPL Horizons goes, but surely it can reach the era
    of Stonehenge. It uses a special long term precession model for dates
    before 1800 (I think) and the latest JPL long ephemeris, the DE431.
    There's considerable uncertainty about delta T in the remote past, and
    that's an issue for some ancient events. But it doesn't matter for
    alignments, which deal with rise and set azimuths, and perhaps altitude
    at culmination. These are a function of the direction of the pole but
    not Earth's rotation about the pole.
    Earthquakes don't seem to have any significant effect on Earth
    orientation. Even after a major one, I see no bulletins from the IERS
    regarding a jump in the polar motion and offset of the pole.
    You'll probably get a more informed answer at the HASTRO-L (History of
    Astronomy) discussion group.

    Browse Files

    Drop Files


    What is NavList?

    Join NavList

    (please, no nicknames or handles)
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.

    Email Settings

    Posting Code:

    Custom Index

    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site