One of the interesting features about Jupiter is the Great Red Spot (GRS). The GRS is a vast storm, spinning like a cyclone. I learned that the GRS would transit on September 28, 2009 around 11:17 PM EDT (you can get that information here) so I setup my DS-90 and got ready to watch. I know that this happens often enough that it shouldn’t be a big deal but, I never took tje time to really look at the event. The moon on this night was waxing gibbous and shining brightly just left of Jupiter.
I focused on Jupiter at x40 and then dropped in my 11mm Plossl for x90. Much to my disappointment, the planet seemed to boil. This is an effect of the atmosphere known as “Seeing”. While the sky was transparent, the view was poor. You can learn more about Seeing and Transparency here.
As I continued to look, waiting for breaks in the turbulent atmosphere, I caught a few glimpses of the GRS which appeared as a light grayish oval at x90. At x117 the seeing was just a nightmare so I stayed at x90 for the night.
I will try to watch this event again in the coming weeks.