Originally Posted by Ricardodaforce:
“Mind you, Jupiter was looking very lovely, so I got the telescope to have a look at it again.”
There was a horrible thin haze here - only the brighter stars visible by naked-eye, and also only the brighter Perseids were visible.

I too resorted to viewing Jupiter, around midnight-ish (with my 1977 Celestron C8 'classic' 8" SCT) - and was pleasantly surprised to see a moon crossing it's face, with it's shadow also on the planet's surface. (an eclipse, if you could stand within that shadow)
'Starry-Night' software confirmed a transit of Europa - the two other moons I could see off to the right (to left in my view, as I was using a diagonal) were Ganymede, close-in, and Callisto further out.
Io was nowhere to be see, but 'Starry Night' showed me it was behind Jupiter from our point of view.
By 1:30, Europa had passed right across the planet's disk, and off to the right to join Ganymede and Callisto.
I also spotted a faint double-star, off to the left (to the right, in my view) - very tight together.
I tried to use it to get best focus for Jupiter
(focusing a star to a pinpoint, gets a telescope to it's sharpest possible focus)
But no matter what I tried, it always looked slightly 'elongated' - so I whacked up the magnification to 350x, and confirmed my suspiscion - a tight double-star.
Slightly de-focused them at this high magnification, to accentuate any colours - and one of them appeared to be bluish, the other pure white.
Gonna stop there, because it's starting to feel a bit like I'm writing up an observing session
Having satisfied myself with a little astro 'fix' - I packed up and came in for a piping hot 'cup-a-soup'