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Sports Weary Observer Reports

Bill Arnett


My eyes were tired after watching both the 49ers and the World Series. So I didn't do much until late. But by midnight the seeing was about 9/10 (normalized for Redwood City :-( Saturn was its usual gorgeous self, minus its usual shadows (it was about a month from opposition). A pesky star complicated satellite identification but I think I caught a glimpse of Enceladus in addition to the Usual Four (plus wide-ranging Iapetus which is easy if you bother to find it); Mimas eluded me as usual.

Moving half a billion kilometers closer to home, Jupiter seemed to be missing a moon. That's not unusual, sometimes a moon is occulted or transiting. What is unusual is that it was clearly visible near the center of Jupiter's disk as a dark spot against the South Temperate Zone. At first I thought it was dust on my optics (of which there is a great deal :-( ) but it stayed with Jupiter when I slewed a bit. It was much too faint for a shadow. So I resorted to the computer and Starry Night then confirmed it as Ganymede in transit. It was just following the Great Red Spot, which seems even less distinct this year than last. The part sticking down into the STZ is almost gone and the interior is very pale. I keep hoping each year that it will get darker but it seems to be the opposite. I couldn't see enough detail to figure out what's happening downstream of the GRS but there's something happening there. Maybe the GRS is about to eat a big oval?

Luna was nice, too. Lots of easy rilles around Posidonius and points north. The Apollo 11 trio were easy. Are they easier near lunar sunset? Seems to me I've seen them more often then than in the other half of the month.

I forgot to close the door to my observatory after I opened it up and came back inside for a while to let things cool off. When I went back out there were wet raccoon footprints leading up to the door but I guess he dried his feet off on my carpet since there were no other prints leading away and no actual raccoon inside :-)


Mail to: Bill Arnett
Copyright © 2001 San Jose Astronomical Association
Last updated: July 19, 2007

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