Jupiter tonight - am I seeing the shadow of a moon?

[Penguin]

Got the TAL-1 out tonight to look at Jupiter through the gaps in the clouds and I can see some moons and a black splodge on Jupiter itself. I assume this is the shadow of a moon, but which one?

This was also my first chance to try out my web-cam and I got this:

There's a dark splodge at 12o-clock and another fainter one at 10o-clock. Could they be the shadow of the moon on the left and the GRS respectively?

I think they were in roughly the same place through the eyepiece but the webcam turned the whole thing by 90 degrees (next time I will rotate the webcam till it matches what I actually see instead of just plonking it in there! It's all a learning curve. I was in a rush to try and get a video on the webcam before the clouds came over again so I had no time to look properly with my eyes.

Anyway, I'd like to know what the two splodges are and to identify the moons. I can't match up the image with what Stallarium shows me. Presumably Stellarium will show it straight when the eyepiece rotates it by 180 degrees.

--- Penguin

[Tantalus]

There are two moon & shadow transits tonight, Penguin. See this thread here http://stargazerslounge.com/observing-planetary/117054-jupiter-transit.html#post1559245

[pvaz]

According to stellarium Ganimede crossed it soon after sunset and Europa is crossing it right now.

Unfortunately every time I plan to see a moon transit on Jupiter I get full cloud coverage... A bit over a year in the hobby, with probably 10+ sessions per month and I'm yet to see a moon transit...

[pvaz]

It seams all it toke was a little rant!

The sky turned to partially cloudy and I managed to get a few minutes when Europa was finishing it's transit. The moon itself wasn't very easy to see, but there was a very pronounced shadow on the opposite side of the disk.

Now it's 100% cloud coverage again... It was short but at least the seeing was excellent, there was absolutely no shimmering at all.