Some interesting Jupiter moon/shadow transits

What an event and clear skies for once!
Although the seeing was terrible it was a fantastic morning full of highs and lows. I was like a child on Christmas eve - only actually managed to get one hour sleep in before getting up at 2am to set up.
Once I opened the curtain and saw clear skies, the adrenaline pumped right through the early hours and on into dawn. The night had a little of everything - wind, no wind, fair seeing, very poor seeing, cloud, dew, fog, ice and a yelping neighbour’s cat for at least 2 hours! There are many ways to skin a cat but one would have done.
The funny thing was the 5 hour session felt like a 30min. Managed to image the spectacle early on but then the seeing it got really bad and of course Jupiter dropped lower to the west. Luckily I continued to keep the film rolling and got a few seconds break from bad seeing. Very happy with a little momento of what will most certainly be a highlight of the year (if not a lifetime ) for me.

Clear Skies!

This is an interesting one - I used three sources of information and all of them showed me that there would be only 2 Moons and 3 shadows simultaneously visible on Jupiter with Io exiting transit before Europa entered transit but it was suggested to me today that my information was wrong and that there was indeed three simultaneous transits (his information was obtained from the farmers almanac). I dismissed this as a mistake until I see Johns comments on this post stating that you could see 3 moons and 2 shadows on the face of Jupiter at the one time. Can anyone confirm which is correct and what the most reliable source of information is? I might be surprised to find that my free Chinese iPhone app is actually not the most reliable source of Galilean moon transit times : )

Yes you're spot on Kevin; all 3 shadows from 6.26-6.52 and all 3 satellites from 7.08-7.12. I have a list of these events covering the years 1980-2040 and can't see a repeat performance during this timespan. Seems to me the rarity value of the 2nd triple transit was somewhat upstaged by the shadow dance.

Here's the reliable S&T utility:

www.skyandtelescope.com/wp-content/obser..._moons/jupiter.html#

And here's an amazing compilation:

spaceweathergallery.com/indiv_upload.php?upload_id=107810

That’s interesting and I would say the discrepancy comes in due to the definition of ‘transit’ and whether it’s the full disc of the moon or whether a partial disc can be regarded as a transit? I notice on Skyweather they show the three moons albeit partially crossing Jupiter simultaneously - but they specifically name it a Triple Shadow Transit rather than a Triple Moon Transit.

Good point, I think the times quoted refer to first/last contact and with only a 4-minute window the discs would not be in full transit simultaneously.

It's a moot point for me anyway as Io in particular was difficult to pick out at any stage.

Thats a nice pic Kevin.
I'm glad there are other people out there who get a kick out of seeing these events