September 29, 2014

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image by Martin Stenke, Leer-Logabirum,Germany

Here is an image from a new contributor to LPOD, always a happy occasion. This is a good regional view taken with a modest-sized telescope and processed with great care. Every time I see an image like this I think that the photographer should image their way across the Moon, building up a personal atlas. By annotating atlas images with the names of the major features, the photographer would establish a detailed familiarity of lunar geography, or selenography as it is formally known. And creating a second overlay of interesting features would build an understanding of the geological (selenological) processes that constructed the landscape. Here are some features to start with. (1) The Nectaris impact basin dominates the scene, with the dark mare at the the lowest area of the basin, which is surrounded by three rings - Altai, and others that pass through Catharina and Fracastorius. (2) Theophilus, Cyrillus and Catharina demonstrate degradation of roughly similar sized craters. (3) The Apollo 16 landing site was at the edge of the Descartes mountains, anomalous hills that are interpreted as basin ejecta, but may be something else. (5) The dark rays from Dionysius at upper left illustrate how craters can excavate and spread underlying material, dark mare in this case. There are many more teleological stories to tell here. I encourage everyone to go beyond the first step of imaging to deeper explorations.

Chuck Wood

Technical Details
August 14, 2014 at 4.42 MEST. 6 inch f8 achromatic refractor labeled "AstroProfessional" in Germany, made in China, at a focal length of ca. 2000mm with an ASI 130MM cam. Though this camera has relatively large pixels (5,2 µm) it shows some detail. To correct chromatic aberration I used a Baader green filter and a Baader-Zeiss prism. Barlow was a shortened TelekopService 2" ED. I stacked about 700 out of 2750 frames wth AS2 1,5x drizzling and processed the image with Fitswork and Registax6. Here is a larger drizzle variant.

Related Links
21st Century Atlas charts 6, 7 12 & 13.

Yesterday's LPOD: Slopes, Dikes and a Sliver of Illumination

Tomorrow's LPOD: Preaching To the Choir


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