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Jupiter on Dec 4th.

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#1 Eddgie

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Posted 05 December 2012 - 03:40 PM

Sad.. Seeing was 2-5 arc seconds. Getting diskes from the moons was fleeting and never had even a moment of rock steady seeing.

I could see what looked like fast moving sheets of air slipping across the face of Jupiter. The air literally looked fluid many times. Jet stream I guess.

But dispite that, I got back from dinner just in time to get out while GRS was about 3/4ths of the way across the disk, and wow, are the billows that follow it impressive. First time I have really gotten them in the eyepiece lately and I was just amazed. They are sooooo big.

Imagine an old picture of a steam locomotive apporaching at an angle to the viewer with the smoke billowing out from the stack and growing shorter and shorter as the artist tries to render a perspective view. And that is exactly what it looked like to me.

The turbulence immediatly after the GRS is huge. I have never seen turbulance so big on Jupiter. Titanic!

But the "Perspecive" makes it rather broader at first, with a kind of quick taper, then more stretched out as you move further away from the GRS, until it dwindles into the distance (If I can keep the smokestack analogy)>

Such an impressive sight.

But seeing was never great. Most of my observin gwas at 165x, and while the turbulance was very well seen (and took most of my attention), there seemed to be a dearth of detail elsewhere. As hard as I tried, I could not see any of the pale ovals that often show up in the southern equitoral region though I got some hints that there might be some there.

And the amount of festoons in the equitoral belt was very sparse, and in fact, not well seen at all. I could see the bases of where I thought there would be festoons, which these days appear very slightly bluish to me, but I could not really see any of the "Wisp" festoons taht extend into the band.

I thought I glimpsed some slight albedo shading on Callisto, but only once when the seeing was very briefly better, but could not repeat this with a few other observations later.

So, not a great nigth, but the "Great Wake" following GRS is so big and so conspicious, and has so much really large structure in it that even at 165x there was plenty to see.

Wish it could have been better, but it was not bad.. Not bad at all...

#2 Rick Woods

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Posted 05 December 2012 - 06:19 PM

Any Jupiter observation you can walk away with is a good one.

Look at it this way: to get perfect seeing, you'd have to get rid of the atmosphere. Personally, I like the atmosphere.

I can't recall ever actually seeing color on Jupiter. Bluish, you say? Any filters or anything?

#3 Eddgie

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Posted 05 December 2012 - 10:09 PM

No, no filters.

The colors are subtle, and in images the base of the long arching festoons look gray, but at the eyepeice, I seem to see them with a very pale bluish tone. It could just be the proximity to the subtle salmon tone of the belt that it roots in.

#4 Asbytec

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Posted 05 December 2012 - 10:12 PM

The steam locomotive is a great analogy. The taper is obvious. It is a favorite feature, and it changes nightly. One night it might sport bright knots, the next broader brush strokes. They seem to sweep south and east. On nights of great seeing, you can see traces well beyond the GRS.

The SBE does seem to have less detail than the NEB, except for the GRS wake. There is one darker knot preceding the GRS, but at that CM it might have rotated over the limb. There is a darker central "core" feature, occasionally some lighter brushes of light along the northern edge, and very occasionally some detail along the southern edge.

Recently, though, the rift in the NEB appeared to rival the GRS wake. But, that was fleeting, it's less prominent and much thinner. It seems to change on short time scales, too.

Totally agree, very few, if any, distinctly blue thin features whipping into the EZ. And the festoons do appear less distinctly blue than a month or so ago.

Edggie, curious, 165x - 174x is about 30x per inch and the normal magnification I use observing Jupiter. Does seeing limit you to those powers? I was reading about the eye and found that it is basically spherical at 1mm exit pupils. In other words, the eye adds no further aberration, essentially, at those powers. Maybe it's fortunate that my operating magnifications provide that size exit pupil.

Oh! the white ovals are extremely difficult, even in great seeing. I have three sightings to my credit over the past couple of apparitions.

Nice to hear your out observing, Eddgie.

Rick, I gotta comment on color. For me, the belts have always been a very weak ruddy or brown, just a shade away from gray scale. The poles brown and gray. Really, that's about it. One night recently, I noted some ruddy tone in the NTrZ. That kicked off an epiphany.

George and Dean were discussing the NTrZ as yellow, Ivano said Jupiter was almost entirely yellow. Thinking that was curious, I paid attention especially to the NTrZ which I swore was ruddy.

Well, turns out they were right, the NTrZ was indeed a pretty strong Tawny hue. But then an amazing thing happened, one I recognized Tawny I began to see it in the EZ which I had always considered to be pretty much white. Seeing Tawny made white features stand out in the EZ. It happens Jupiter had a wealth of them that night.

Once one cloud recognize those subtle changes in hue, a whole new chapter was opened up on Jupiter. Detail exploded. Normally, to me, the NTZ, EZ, and STrZ and STZ were simply white. But, once white stood out in the EZ, those zones could be seen as "not white." They were indeed grey.

These colors are not bold by any stretch, but they turn out to be very distinct from one another. They are certainly very close to gray scale, but if you can learn to notice their subtle distinctness from one another - Jupiter explodes into color!

I think that's key, not seeing color saturation, but recognizing the slight, but distinct, changes in hue - just a shade or two from gray scale.

The GRS is still very difficult, for me. Only a handful of times have I been able to discern any faint salmon hue. And only once did BA exhibit that same weak hue. But, the festoons, what's left of them, still exhibit some blue out away from the NEB. It's not as saturated as it was a month or so ago.

Sorry for the length...

#5 azure1961p

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Posted 05 December 2012 - 10:59 PM

Norme you make a good point about the transient nature of Jupiter's features. Truly from night to night there is a difference. When I've checked back with the imaging forum for a comparitive or simultaneous image it becomes real clear what happens on very short timescales .

Edd, it was uplifting to read about your experiences. I'm glad the MV Is all that. The white ovals totally eluded me as well.

Pete

#6 Rick Woods

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Posted 06 December 2012 - 12:22 AM

Hmm. I need to concentrate on seeing colors. I have enough telescope for it; if all I see is gray, it's most likely a failing in my eyes.






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