View Single Post
Old 01-09-2018, 08:52 PM
Tinderboxsky's Avatar
Tinderboxsky (Steve)
I can see clearly now ...

Tinderboxsky is offline
Join Date: Feb 2012
Location: Tinderbox TAS
Posts: 683
A busy night for the Jovian Moons

It was an interesting nightís observations following the Jovian moons on the 29th August. Both the seeing and transparency were excellent and the Jupiterís atmosphere was clear and detailed in all itís glory.

Near sunset and not visible, Ganymede started a transit, minutes later Europa was occulted by Jupiter and about 14 minutes later, Io began itís transit.

My first observations were at 7.40pm because of other commitments. At this point Ganymede was very clear and approaching egress. Io was further towards the centre of Jupiter and on occasions, just visible against the dark atmospheric band. Ioís shadow had already commenced itís transit at this stage and was nice and sharp against Jupiter. I watched Ganymedeís egress.

At 8.23 I could see the beginning of the emergence of Europa from behind Jupiter on the opposite limb to where Io was about to commence itís transit egress. Minutes later as Io began itís egress, Europa had just separated from Jupiterís limb. However, Europa had only moved away from Jupiter by about 10Ē when it was eclipsed by Jupiter and disappeared from view. Io was completing itís transit egress at the same time. Just over an hour later, Ioís shadow completed itís transit egress.

I returned to Jupiter at 10.47 to catch Europaís reappearance out of Jupiterís shadow well away from the planet. The GRS was also sliding into view, however the sharp detail was was fading as Jupiter was now only about 10 degrees above the horizon.

140mm refractor and 8mm eyepiece giving 100X.
Reply With Quote