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: The moons of Jupiter for Time or Position?
    From: UNK
    Date: 2016 May 9, 07:29 -0700

    Frank said:

    Tables and charts of the motions of the Galilean moons of Jupiter were included in the

    > Nautical Almanac & Astronomical Ephemeris from the very beginning, starting in 1767,

    >and they were published in other resources long before that.

    I was taken aback when I first read this, since one would need a pretty good estimate of the speed of light in order to correct for the relative positions of Earth and Jupiter in their orbits. To my surprise I find that as early as 1728 James Bradley had determined a value that was off by less than one part in 20. See: http://www.speed-light.info/measure/speed_of_light_history.htm

    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