Io Transit

by Richard Navarrete


I read Akkana's initial post a little after 10 and even though she reported poor seeing, I figured I'd haul out Professor Plum, my homemade 8" f/7 dob. It's stored in an unheated outdoor shed so cooldown wasn't a problem. My first views were spectacular with lots of detail. The GRS and the shadow of the moon and the white dot of the moon itself were stuning! I went back into the house and got the bino-viewer after 5 minutes or so. When I got back, the seeing was BAD! At one point, I was watching an interesting dance of the other three moons, clustered almost like an isocoles triangle. Each of the moons was tripled! It was as though there was a steady, gentle thumping on the ota to make the image dance. There were moments of good seeing, but mostly horrid. Paul Sterngold in Alameda said the seeing improved around 9:30. Did you notice the seeing go bad later?

My impression was that the moon and shadow near the limb was almost a figure 8, with the moon and it's shadow just barely touching. Difficult to really tell with the swimming image.