Jupiter - quick "grab and go" session

[John]

Just come in from a quick "grab and go" session on Jupiter with my 4" refractor. At 1:15 BST I could see:

- Io just going behind Jupiter - about 50% of the moons disk was showing as a "bump" on Jupiters limb.

- 2 moon shadows (Ganymede and Europa's shadows) on the disk plus one darker and larger disk which I presume was Europa actually in transit from the other reports. These all fell within the Equatorial Zone.

- Callisto way off to the east of the planet (my mirror diagonal shows N & S correctly but E & W reversed - I think !).

- The GRS more or less on the central meridian with some darkening at the edges of it's hollow in the South Equatorial Belt.

- 4 belts - the NEB, SEB, NTB and what I take to be the SSTB. The NEB and SEB shown uneveness along their edges and some variations in contrast.

- Darkened north and south polar areas.

I've not checked to see if the GRS is where I think I saw it but it was clearly seen as far as I was concerned tonight. Sombody will probably now tell me that it was actually on the other side of the planet at the time of this session which will be a bit embarrassing !.

Clouds restricted this session to only 20 minutes or so but I'm so glad I made the effort - what a great show from the giant planet

John

[Rusty Strings]

I caught that too. I began at 10 past midnight and stayed awake until 01.40. When I started there were two shadows in the equatorial region from centre to west (Ganymeade /Europa) and what appeared to be a disc on the western limb, could this be Europa's disc?. At around 01.15ish Io disappeared Jupiter. I noticed a third, smaller shadow following Europa's shadaw after the western limb disc had moved round, can anyone explain what that may have been??

John

[John]

I caught that too. I began at 10 past midnight and stayed awake until 01.40. When I started there were two shadows in the equatorial region from centre to west (Ganymeade /Europa) and what appeared to be a disc on the western limb, could this be Europa's disc?. At around 01.15ish Io disappeared Jupiter. I noticed a third, smaller shadow following Europa's shadaw after the western limb disc had moved round, can anyone explain what that may have been??

John

I saw the 3 dark spots strung out along the Equatorial Zone at 01.15 BST. One (the middle one) was darker than the others. I took the 2 slightly fainter ones to be the shadows of Europa and Ganymede and the darker one to be the silhouette of Europa itself as it crossed the disk, although it could had been Ganymede I guess - can anyone offer a definitive ID on the darker spot ?.

John

[Kieron]

Hi John(s),

The darkest spot (centre one of the three, and above the GRS) was Ganymede's shadow. Preceding this (to the right, assuming south down) was Ganymede. The other dark spot was Europa's shadow. Europa itself probably could not be seen, because of its high albedo.

Here is a not very good image that shows all of the above, with Io just disappearing behind the preceding limb.

Best wishes, Kieron

[John]

Thanks for that clarification Keiron - it's good to know which dark blob is which moon / moons shadow !.

Your photo (which I think is great !) shows exactly the view I saw when I started my session at 01:15 am BST, including a slight darkening in the SEB just in front of the GRS / GRS "hollow" - I'm rather impressed that my little Vixen ED 102mm allowed me to detect that feature .

Thanks again,

John

[Rusty Strings]

And a thanks from me too Keiron, just as john says good to know what I'm looking at,

nice image too.

John

[John]

Thanks for that clarification Keiron -

Oops ! - sorry - it's Kieron

John

[mdstuart]

I saw this as well if you look at my other posts. I started a little earlier and only saw two spots and a moon dissappear on the right of the planet in my dob at 12.30.

It really was an amazing view, I have never seen this before.

I gather there is a similar show on August 27th but from 2.42 so a late one!

Mark

[John]

It really was an amazing view, I have never seen this before.

It certainly was amazing and a 1st for me as well Mark

John

[Rusty Strings]

A first for me, I was amazed what was unfolding before my eyes, I almost didn't bother going out. First time I'd seen the GRS too.

John

[mdstuart]

No.... everyone has seen the GRS but me........

Mark

[Rusty Strings]

It wasn't that easy to see, I had to look at jupiters disc for a long while trying to decide if I could see it or not then a moments atmospheric clarity swayed the argument.

John