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Aug 30-31: Rilles

Talitha

By Talitha
in Observing - Lunar

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Talitha

Talitha

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The seeing on August 30-31 wasn't as tremendous as the previous night, but there were still some better than average pockets which lasted for 10 minutes or so. The highlights of the session were the rille systems of Janssen, Goclenius and Gutenberg. I never saw them this clearly before, and they definitely never showed up this good on the images. I'm wondering if the light angle at sunset shows them better than at sunrise, though.. that might have something to do with it.

The Quad Maps list Janssen (first image) as having only one rille, 'Rima I'. It's the large curve extending from the southern edge of Fabricius and ending on the southern end of Janssen P's floor. Outside of Janssen P, the rima branches out like a river delta.

Rimae Goclenius and Rimae Gutenberg were soft and thread-like, and reminded me of Rimae Triesnecker. There's no way I can properly identify them or describe where they extend, but you can find them labelled here and here.

The second image is a scaled-down crop of the area. Tweaking seemed to ruin the clarity instead of improving it, so I just left it alone.. but you can still see the faint rimae. Again, I'm not sure if sunset shows the features any better than sunrise, but this is the most I'd ever seen in the area.

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The Warthog

The Warthog

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Some of this stuff is pretty faint, but I am getting more and more into looking for these features, the more I find what to look for. I think my 105mm refractor seems to be about the minimum for finding really delicate stuff. I've promised myself an 8" SCT when I retire.

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Talitha

Talitha

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WH, I think you'd like an 8" SCT... it's great for lunar work (and even better when the seeing co-operates). :wink:

Thanks Martin! :( To be perfectly honest, I'm never sure where to post. Do you think it would be better to post the text portion of the report here and place the images in the imaging forum? ;)

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Cloudwatcher

Cloudwatcher

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Many thanks for that report Talitha. Done with style and very interesting to me as I find the Janssen area of particular interest. There always seems to be something new to be seen under changing lighting conditions in that region wether waxing or waining.

Out of shot in your image, towards Piccolomini there is a feature seen on several occasions that I refer to as the "Arrowhead",just because that's the image it brings to mind. As you seem very well versed in Luna detail I was wondering if you are able say whether this is an actual feature or simply a trompe l'oeil effect visible only in certain lighting conditions?

The attached is an enlarged section of a widerfield so not of the best quality but I have hi-lighted the area as best I can and hope you can see what I mean.

Keep those reports and images coming. 8)

CW

(Click to enlarge a liitle bit more.)

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Talitha

Talitha

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No, I saw this post as a post on observing illustrated by photography, rather than a post about the photographs themselves. 8)

Thanks WH, I wasn't sure if there were any restrictions. :(

Martin, thanks for feeling that my images were good enough to be displayed in the imaging forum... your compliment is well-apprectiated. ;)

Basically though, I use images as observing tools.. a way to share the eyepiece with other lunar observers, and point out interesting features. It's probably why I feel more at home in an observing forum than an imaging forum.

But when a night of extraordinarily good seeing has allowed me to get some fabulous images, you'll see me in the imaging forum.. I promise. :wink:

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Talitha

Talitha

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Thanks, CW! :wink:

I've seen your 'arrowhead' a few times.. very interesting! When time allows, I'll go through my images to see if it's ever been captured. If it has, a quick check with the VMA program will tell me what the libration was. Maybe that's the key element.

Here's a crop from another image taken the night of Aug 30-31. Although you can detect the features which produce the arrowhead, there were no distinct shadows. Isn't lunar observing fun? ;)

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Cloudwatcher

Cloudwatcher

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What an amazing discovery! This is obviously the runways for the flying saucer people's spaceships. The control tower must be hidden under, or disguised as, an outcrop of rock. I'll have to watch this space very closely in future. :wink:

OMG WH, your right! ;)

You've just reminded me of another in the series covering this region which contains a curious shadow that doesn't fit well with others in the area. It's far darker than it should be and with sharp well defind edges. Allowing for the length of the shadow it's proportions must be 'Monolithic'! I will have to check but from memory I think it's frame No. is '2001'. Watch this 'Space' indeed! This could prove to be quite an 'Odyssey'.

Cheers

CW

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barkis

barkis

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I think your avid interest in the moon, and It's many and varied features, which you catalogue so expertly, do you great credit Carol.

You are certainly going to have an impact on a few members regarding paying closer attention to our near neighbour.

I never tire of observing the moon, simply because it offers so much shadow changing detail.

IMHO, I believe my best views of certain lunar features, presented themselves a lot clearer as sunlight receded from the surface.

Have you had an opportunity to image those rilles when the sun is even lower , and the terminator very close?

Also Carol, I think Sir Patrick Moore would invite you to his Sky at Night programme, if you agreed to take along your Lunar Sketches.

He could build a few shows around that I reckon. As you know, the Moon is very close to his heart, and you would become very good friends I am sure ;)

Please keep up what you do, It's brilliant.

Ron. :wink:

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Talitha

Talitha

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:colors: Thank you Ron and Steve!

Gee, I'd love to meet Sir Patrick moore! ;)

You are certainly going to have an impact on a few members regarding paying closer attention to our near neighbour.

If I can convince even one deep sky observer not to bemoan Luna every month, my time will have been well spent. :wink:

Have you had an opportunity to image those rilles when the sun is even lower , and the terminator very close?

Yes, and I recant my previous claim of seeing CW's arrowhead. Mine is a different one although it's in the same area. Here's an image from Sept 3 2004 (and a clean copy, too). CW's arrowhead is in yellow, mine is in blue.

(Sorry about the poor image.. it's what my 'average' seeing produces.)

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The Warthog

The Warthog

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Gee, I'd love to meet Sir Patrick moore! ;)

You and me both. I'll have to see if there's any possibility when I get to England in the next few years, as long as he holds out. I wonder if he would sign my Boy's Book of Space?

You are certainly going to have an impact on a few members regarding paying closer attention to our near neighbour.

If I can convince even one deep sky observer not to bemoan Luna every month, my time will have been well spent. :wink:

Partly as a result of these discussions, partly as a result of re-reading Sir Patrick's Survey of the Moon, and largely because, between my ruined eyesight and the LP and transparency issues in my back yard, I've decided to concentrate on lunar astronomy. I am finding searching for DSOs in this climate more frustrating than satisfying, but I always come away from the Moon relaxed and pleased with the night. Reading Survey again reminded me that the wealth of observations to be made on the moon is really more than one can easily imagine. The pressure on me with the moon is going to be to see finer and finer detail.

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