Telescope Reviews: Interesting Phocylides and Nasmyth feature

Hello all –

I would like to share a lunar feature that I found puzzling, and then, after a little research, very interesting. I thought that I would bring it up because I have not seen this topic in any forums.

I was imaging the Moon’s terminator with my Meade LPI camera attached to my Celestron Super C-8 Plus at approx. 9:20pm on September 30th. (01:20 9/31/09 UT). This would put the Moon’s age at about 12.26 days.

When I examined the images the next day, I noticed what appeared to be a horizontal glitch on one of my images. I was sure that a large piece of dust had landed on the LPI’s chip, or that the data was somehow corrupted. However, the very next image overlapped the same area, and the glitch was still there, but on a different part of the chip. I then started to refer to it as a FEATURE, not a glitch. The craters involved are Phocylides (top) and Nasmyth (bottom). The larger crater below the circle is Schickard. North is down, and East is to the right in these images.
See the circled area of the image below, and the un-circled area on the subsequent image:
http://www.flickr.com/photos/burbscope/3987479558/in/set-72157622528968210/

http://www.flickr.com/photos/burbscope/3987480164/in/set-72157622528968210/

Here is a 4X enlargement of the horizontal feature.:
http://www.flickr.com/photos/burbscope/3987480300/in/set-72157622528968210/

http://www.flickr.com/photos/burbscope/3986727361/in/set-72157622528968210/

After a bit of web surfing, I ran across the following article in the Journal of the British Astronomical Association.
“The Topography of the Phocylides and Nasmyth Area of the Moon” by D.G. Buczynski and P. Wade
(as archived by SAO/NASA Astrophysics Data System (ADS) at:
http://articles.adsabs.harvard.edu/full/1985JBAA...95..106B)

Please read the article, which provides a detailed explanation of illumination conditions, the difference in crater floor elevations, and the wall between the craters.

It was very interesting to me to find an illustration in scientific literature (as sited above) that so closely matched an image of mine, taken many years later, and probably within a hour or so of the moons age. Pure serendipity.
(I am reproducing an illustration without permission, but I believe that I have given adequate credit).

http://www.flickr.com/photos/burbscope/3987516548/in/set-72157622528968210/

I did a fair amount of searching, and I have not found any images of this area under similar lighting conditions.
I have seen some jaw-dropping lunar images on Cloudy Nights, so I hereby challenge you experts out there to get a hi-res image of this area under similar lighting conditions (a couple of days before the full moon). Please post your results here!

Edited by burb scope (10/07/09 08:05 AM)