Attached is a sketch I made the night of Nov 7, 2010. At the time I just wanted to catch Io's transit and shadow across Jupiter but I kept noticing a high contrast area that was distracting. I made a note of it but didn't think anything of it. Then i saw Christopher Go's image of the dark plume on spaceweather.com and thought "did I see that?" Does anyone know how I could confirm this--perhaps back-track the rotational period back to Nov. 7th and see if the dark plume lands on the meridian (which is where I have it drawn)? Thanks!