Hi all, When I checked out the Sky & Telescope web site below (from Patrick's News), it had a great animation of the moon occulting Jupiter, on the third page. What I can't understand is why Jupiter is in sharp focus while the moonscape is slightly fuzzy. It isn't possible that there could be a real difference in focus between the two, I believe -- granted, Jupiter is thousands of times farther out, but for all practical purposes the focus for both should be at infinity. Or is it because the telescope was tracking on Jupiter, making it relatively stable, but the moon had some lateral motion for each exposure, causing blurring? Just curious. Also, if anyone has a minute, can you tell me why it's necessary to focus a telescope at all? You would think that, like an old Instamatic camera, everything beyond a few miles out would be at the "infinity" focal point. I know that's not true, but I do not understand why. Thanks, Joe
News, Wednesday, 09 FEB 2005
Celestial Highlights for 2005
Eclipses, conjunctions, and occultations -- as well as plenty of "regular" activities like meteor showers -- will keep observers worldwide busy during the upcoming year.
http://SkyandTelescope.com/observing/highlights/article_1456_1.asp +++++