Nightspore Posted September 25, 2022 Share Posted September 25, 2022 (edited) I got 'Big Mak' out for a bit last night. The seeing was great, I could just about see the Milky Way with the dodgy humidity, and thankfully the jet stream missed the Midlands (but not Scotland lol). Unfortunately the humidity at this time of the year precluded getting more than about 128x maximum. The sharpest was at about 100x. I could distinctly see Europa as a black disc against the limb until it became visibly bright as it pulled away from Jupiter. The GRS was easily seen and I could perceive some detail in the NEB and SEB. Jupiter was incredibly bright and appeared huge at nearly 50 arc seconds. I needed polarising filters at one stage. I also used Baader Light Blue, Semi-Apo and Neodymium filters. This is probably the nearest I'll get to the opposition due to inclement weather (no surprises there then). So, apart from not getting higher magnifications I'll class this as a success. I was surprised that I could actually see Mars. Although I had to reposition Big Mak slightly. The planet looks quite big at 11.4 arc seconds and 86.9% illuminated. However, at barely 17° altitude and combined with the humidity I didn't actually expect much. At magnifications between around 180x and 256x I could see the phase quite distinctly. The southern polar cap wasn't obvious but I'm pretty certain I could just about make out a tiny white point. The possible NPH clouds were also still present albeit a tad muted. The darker albedo features in the above screenshot were hinted as well. I used the Baader Semi-Apo filter. Edited September 25, 2022 by Nightspore 2 Quote Link to comment Share on other sites More sharing options...
Nightspore Posted September 26, 2022 Author Share Posted September 26, 2022 I am curios about the black disc of Europa visible against the planet surface. I'm not sure whether I was seeing a silhouette of Europa contrasted against the bright surface or a transit shadow. I suppose it could depend on the amount of phase perceived of Europa itself. Quote Link to comment Share on other sites More sharing options...
FracTak Posted September 27, 2022 Share Posted September 27, 2022 (edited) 23 hours ago, Nightspore said: I am curios about the black disc of Europa visible against the planet surface. I'm not sure whether I was seeing a silhouette of Europa contrasted against the bright surface or a transit shadow. I suppose it could depend on the amount of phase perceived of Europa itself. At Opposition, the moons will show 100% phase as they too are opposite the Sun. In addition, the shadows are very close to the moons, actually eclipsed by them at opposition but very close on Sunday, so you likely saw both moon and shadow close together. From my experience it is only Callisto and Ganymede which show as dark against the Jovian surface due to their lower albedo. Edited September 27, 2022 by FracTak Quote Link to comment Share on other sites More sharing options...
Nightspore Posted September 27, 2022 Author Share Posted September 27, 2022 (edited) 3 hours ago, FracTak said: deleted Edited September 27, 2022 by Nightspore Quote Link to comment Share on other sites More sharing options...
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