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    Re: Time and Longitude by Jupiter's moons
    From: Frank Reed
    Date: 2024 Dec 8, 09:15 -0800

    Sean C, you wrote:
    "Now I have a 120mm refractor (pictured below) with a maximum useful magnification of about 280x. I have seen the moons many times, I just haven't timed their eclipses."

    That sounds like (and looks like) an excellent choice for watching these eclipses. We should plan for an upcoming Ɪo or Europa eclipse and see how many observations we can get and to what extent they disagree. Part of the process in the time of Cassini was apparently to ensure that all observers were similarly trained and equipped with similar telescopes. Can we manage without those constraints? And how can we simulate some level of uncertainty in the time before the eclipse? Maybe set an analog watch (or equivalent app with time that is not automatically corrected)... get a friend to change the time by some unknown offset on the order of five minutes... and avoid looking at accurate time for an hour before picking up the watch to plan for the observing session...

    Frank Reed

       
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