Re: Ganymede transit Thursday night

From: Glenn Hirsch (glenn@No-Spam)
Date: Fri Feb 28 2003 - 10:32:59 MST

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    I saw it too! Certainly made my evening...

    >> Michelle wrote: Seeing is good.
    >>Transparency excellent. The planets tonight were stunning.
    >
    >Did you happen to catch the Ganymede transit tonight on Jupiter? I
    >had the 7 inch Starmaster Oak Classic in the backyard near Stanford,
    >and we had some of the steadiest seeing I have seen locally in
    >weeks. Ganymede was obviously dark against the surface of Jupiter
    >when near the middle of the planet around 9:15 pm , but then got
    >hard to see as it approached the limb, and finally turned to a
    >whitish dot superimposed on the limb of Jupiter just before emerging
    >from the planet around 10:30 pm. A great example of limb darkening
    >on Jupiter! (Io and Europa are normally harder to see when in the
    >middle of the planet than at the edge. Ganymede has a darker
    >surface and showed the opposite pattern). The GRS was perfectly
    >placed near the meridian during much of the transit, behind
    >Ganymede itself, but preceding Ganymede's shadow. The shadow was
    >bigger, darker, and sharper edged than the moon itself, and the two
    >dark spots made a great set of brackets for the pinkish GRS. Just
    >after Ganymede emerged from Jupiter, it made a beautiful tight
    >double star with Callisto. Minutes later, Callisto went into
    >eclipse behind Jjupiter, as Ganymede was moving further away.
    >Humidity was high but the views were often rock steady for minutes
    >at a time. Hope the good viewing continues into the weekend both
    >at Plettstone and at sites in the Bay Area.
    >
    >David Kingsley



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