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A busy night for the Jovian Moons
It was an interesting night’s observations following the Jovian moons on the 29th August. Both the seeing and transparency were excellent and the Jupiter’s atmosphere was clear and detailed in all it’s glory.
Near sunset and not visible, Ganymede started a transit, minutes later Europa was occulted by Jupiter and about 14 minutes later, Io began it’s 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. Io’s shadow had already commenced it’s transit at this stage and was nice and sharp against Jupiter. I watched Ganymede’s 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 it’s transit egress. Minutes later as Io began it’s egress, Europa had just separated from Jupiter’s limb. However, Europa had only moved away from Jupiter by about 10” when it was eclipsed by Jupiter and disappeared from view. Io was completing it’s transit egress at the same time. Just over an hour later, Io’s shadow completed it’s transit egress.
I returned to Jupiter at 10.47 to catch Europa’s reappearance out of Jupiter’s 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.
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