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Old 22-06-2010, 01:22 PM
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12 Plato Craterlets, 332km from the lunar surface

After a solid month of solid overcast, a rare not-so-clear night presented itself.

With the moon nice and high, I ended up observing it for perhaps the better part of 2 hours. Seeing was very inconsistant, a bit mushy but with instances of crisp viewing. Patience was the word of the night INfact, it might have been somewhat worse than average, as stars didn't focus as tight as they normally do at high power. Plus, there was extensive high cloud aswell.

Ofcourse, a few days ago I took the secondary mirror out, but after I re-installed it I forgot to collimate it and when it hit me, it was way too dark. But it seemed to look alright under the dim illumination of the car jump-starter light. Could be better though.


Date: 21/6/2010
Scope: 12" F/4.4 truss dob
Time: 7:45pm-11:30pm
Seeing: 4/10
Transparency: 1/5

After spending some 2 hours on the moon, I have made the following observations.

The view at 381x was very crisp, bright and sharp, I was surprised. Last time I remember observing the moon at this power, all I got was a fuzzy ill-defined view. I increased power to 534x which I settled on, and while seeing was blurring every now and then, there were instances of remarkable detail.

For Plato observations, I am using David Knisley's excellent guide:
http://www.cloudynights.com/ubbarchi.../o/all/fpart/1

Plato
The Big 4 craterlets A,B,C,D were amazing at 534x, nice big pits with the shadows of the rims across their floors. C and D were well resolved with a nice big wide gap between them. Craterlet G was resolved into a pit and H was seen aswell, but a double with two tiny pits, it was not resolved as such. Cratelet E was easy, also resolved into a pit.

Also spotted I, J, K, N, P. THese were much more difficult, but in moments of steady seeing, were obvious, particularly I and J. I could even resolve I and J into tiny pits at 534x momentarily in bouts of good seeing. The most difficult of this lot were K, N and P, all three only seen as tiny white spots intermittently. I may have suspected resolving the pit of K, but cannot confirm.

Other features seen on Plato inlcude a tiny area of brightness between craterlet E and P, and a "ribbon" of bright material across the northern side of the crater.

Rupes Recta (straight wall)
Fantastic at 534x, certainly didn't appear straight that's for sure! THe wall appeared very uneven, and some "peaks" or "benches" could be seen in the sunlight in the otherwise dark area from the shadow of the wall itself.

Alpine Valley
Nice wide cavern at 534x, could even see the Rille down in the valley floor.

--------------------------------------------------------

Spent some time cruising the lunar terminator, and was amazed at the detail, particularly Copernicus at 534x. Those terraced walls were killer, the intense detail in the crater floor, can't explain it, it's like severe granularity in a globular cluster or a mass of grapes or something.
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Old 22-06-2010, 01:42 PM
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Dave47tuc (David)
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Thanks for the write up on one of the best objects to observe in the sky

Scope working well then? your able to track nicely at those mags with the scope? of course

Got to get you down with the 18" again so you can start thinking of going bigger than the 12

Cheers mate.
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Old 22-06-2010, 03:13 PM
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Paddy (Patrick)
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Thanks for the report, Sab. It seems we don't often post reports of lunar observations - as Dave says, its a great object to observe. Especially at 534X!
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Old 22-06-2010, 06:00 PM
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Quote:
Originally Posted by Dave47tuc View Post
Thanks for the write up on one of the best objects to observe in the sky
Biggest source of annoyance visual pleasure in the sky it is, no arguments there!

I always tend to avoid going out when there is a moon but glad I did last night. I gotta get out there more often when the moon is up.



Quote:
Scope working well then? your able to track nicely at those mags with the scope? of course

Got to get you down with the 18" again so you can start thinking of going bigger than the 12

Cheers mate.
THe improvement over the original scope is quite startling tbh.

Should start putting away the pennies right now for a fully loaded 32" SDM in a 6.7m Sirius dome



Quote:
Got to get you down with the 18" again so you can start thinking of going bigger than the 12

Cheers mate.
We must! I still haven't forgotten the view of Thors Helmet and Tarantula Nebula with the 18". Beyond spectacular really.

Last edited by pgc hunter; 22-06-2010 at 09:02 PM.
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Old 22-06-2010, 06:12 PM
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Originally Posted by pgc hunter View Post


Should start putting away the pennies right now for a fully loaded 32" SDM in a 6.7m Sirius dome
Better not point that at the moon, your eyes might never recover.
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Old 22-06-2010, 07:16 PM
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Quote:
Originally Posted by Paddy View Post
Thanks for the report, Sab. It seems we don't often post reports of lunar observations - as Dave says, its a great object to observe. Especially at 534X!
I could've gone higher, just for fun I tried 667x and 800x I could actually see a fair amount of detail, and while it was not as asthetically pleasant as at lower power, it really was only the seeing blurring it. Plato's biggest 6 craterlets were still there at 953x. But seeing was far too poor for such nutjob mags for a start, then other factors such as diffraction etc start to come into play. Give me perfect seeing and I'd estimate mags up to 800x would be perfectly within reason.


Quote:
Originally Posted by Paddy View Post
Better not point that at the moon, your eyes might never recover.
That's why we have these special welding glasses with features spoecially designed to observe the moon and bright DSOs in huge scopes:

-Special SAB design

-All black optics for optimum eye protection

-Anti eye melting technology, so you don't end up like Lumpy in Happy Tree Friends

-Professionally crafted using a lighter flame to a piece of glass for high performance, safe viewing of the moon, M42, Sirius etc

Last edited by pgc hunter; 22-06-2010 at 07:40 PM.
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Old 25-06-2010, 10:08 PM
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The floor of Copernicus looked like a mass of caviar, it was quite astounding.

The Straight Wall as I saw it at 534x looked pretty much identical to this image:
Attached Thumbnails
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Old 28-06-2010, 10:35 AM
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goober (Doug)
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Wow... 12 craterlets? I don't believe you ... or I don't want to believe you Nice job.

My lunar observing is naked eye with my boy. He now knows "moon" and "Venus" ... pretty good at 18 months.
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Old 28-06-2010, 11:03 AM
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Wow... 12 craterlets? I don't believe you ... or I don't want to believe you Nice job.

My lunar observing is naked eye with my boy. He now knows "moon" and "Venus" ... pretty good at 18 months.

Hey, been a long time since we heard from you mate! I miss your excellent obs reports It could've been 13, but craterlet F was in the shadows. Plus I failed to see W and O, which seem to be larger than the smallest ones I saw, so that's 15 potential Bring on 3rd quarter

I was out this morning and was following the limb of the moon at 762x, seeing was a bit crap, but the detail I saw at a much crisper view at 381x was all there.... it was awesome seeing the hills and mountains along the edge of the moon and also great detail in instances of steady seeing, it s like being over the moon in a space ship Also viewed some crater at 1144x which showed striations, texture in its bowl. The central peaks in Langrenus and Petavius this morning (28/6/2010) at 1144x
were actually well resolved!

Just for fun I decided to lash up the powermate and 2x barlow for 2000x and unbelievably I could still see some detail on the moon (ofcourse blurred by seeing and killing the scope), when I expected to see nothing but a complete blur

Because of this scope, I am increasingly wanting the moon to be around all the time! Sorry all you faint galaxy lovers


On the flipside, I put in my 22mm LVW for a wide field 60x on the moon... beautiful scene ... then I was literally blind in my right eye for a full half hour!

Last edited by pgc hunter; 28-06-2010 at 06:36 PM.
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  #10  
Old 28-06-2010, 12:04 PM
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Because of this scope, I am increasingly wanting the moon to be around all the time! Sorry all you faint galaxy lovers

hahahahahahahahaha :lol :
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