Jupiter 18/03/14 19:30 - 22:00

[jabeoo1]

Yesterday afternoon reading the thread 'To get better views of Mars with a 250px.. New Barlow or Eyepiece?' highlighted the need to concentrate an observation session on one object in order to really see those moments of exceptional seeing.  I took advantage of an unexpected clear sky last night where transparency seemed very good for the city.  So with NO sky surfing on the agenda I set up and got comfortable for a few hours.

The seeing varied in extremes, sometimes swinging suddenly back and forth in brief time frames, this was managed by juggling between eyepieces as conditions changed.  Currently I have no 10mm or 11mm eyepiece to fill the gap between x106 - x200 & this mid point would have been very useful last night.  But the main detailed seeing was very possible and in at times very rewarding at x200.  

Brief Observation report:

I noticed the 4 moons looked to be evenly spaced on one side of the planet, in order from innermost first, Io, Europa, Callisto & Ganymede.  I thought this gave me a good opportunity to see how they drift relative to each other over the next few hours.  I noted by the end of the session that Io & Europa had drifted to look 'close' whilst the outer 2 moons looked only slightly shifted.

The planets disk showed in times of the worse seeing as a slightly distorted disc with the obvious but blurred equatorial belts with an appearance of lost detail bleached out to an over-exposure.  In times of middle ground seeing the 2 equatorial belts showed up more clarity with blurry straight edged boundaries of various shades of muted color.  Other bands and belts also showed up creating the feeling of seeing a 3D object rather than a flat 2D disk. The rewards were reaped in the times of steady seeing where deeper detail was glimpsed for around 10 seconds at a time.  I noted the main equatorial belts had taken on contrast and clarity to the edge where undefined fuzzy straight lines gave way to curves and angular changes over the cream gases.  The suspended motion of the darker gases on lighter cream during each brief window of glimpsing was apparent and changes in shape and positions of many features showed to have moved between these short 'tuned' in views.  The Great Red Spot appeared in times of good seeing completely budded off from the nearest belt with a nice curved channel of lighter gas space between the spots darker edge and curved belt edge.  I noted that this was the most defined view I have had to date of these surface features.  Over the space of a few hours the details on the planets active surface had noticeably moved and changes of the shapes and positions of the features were without doubt.  I noticed another feature that may have been the smaller red spot or a belt prominence that was oval in appearance.  

All in all a very rewarding session that makes me wish for that evening of long period exceptional steady seeing.  The detail this scope shows when the UK weather allows is at times beautiful, and the patience in the waiting well worth while.

Clear Skies all.

     

[jabeoo1]

Did anyone image or sketch the big planet last night around this sessions viewing time?

I would love to see what I saw

[Mike73]

Sounds like x200 was the perfect mag for you last night James, I think I've used around x180 most of the time this winter for Jupiter it s just a case of finding the sweet spot between seeing conditions and magnification.

The last time I saw the GRS it almost appeared to have a darkened band going all the way around it and that gap between the GRS and the RSH (Red Spot Hollow) was quite striking because of another dark band across the SEBs.

No sketches from me I'm afraid.

[jabeoo1]

Sounds like x200 was the perfect mag for you last night James, I think I've used around x180 most of the time this winter for Jupiter it s just a case of finding the sweet spot between seeing conditions and magnification.

x200 did the job Mike but I agree that slightly less would have given up more more frequently.

The last time I saw the GRS it almost appeared to have a darkened band going all the way around it and that gap between the GRS and the RSH (Red Spot Hollow) was quite striking because of another dark band across the SEBs.

Ah so thats the terminology for what I was describing then.  The Red Spot Hollow, yeah it was clear as day for small amounts of time.  Really really impressed with seeing so much detail in such a 'small' area.

No sketches from me I'm afraid.

Shame I was hoping !   Maybe someone else will pull something out the bag.