image by Jérôme Grenier
Where to begin? Western Tranquillitatis is such a feature-rich area of the Moon, and Jérôme’s image is so magnificent, that many, many wonderous objects are visible. Middle-left is the concentric mare ridges named Lamont - perhaps a buried two-ring impact basin. Just northwest of Lamont is shadow-filled Arago crater with its two rugged domes, Alpha above and Beta to the left. Northwest of Alpha is a line of three smaller domes (partly obscured by a dark defect), and northeast is a beautifully domey mound. Rilles and rille-like features abound. The famous Diamondback Rille winds through the bottom right corner, a closely-spaced crater chain is about 60 km (2.5 Arago diameters) north of the rille, and another straight crater-chain(?) rille extends to the southeast from near Carrel (top right). The last two features are parallel to each other and to at least three mare ridges between Lamont and Maskelyne (near bottom right). These five linear features are roughly radial to Imbrium, but I am not certain that it is Imbrium that structurally controls their locations and orientations. What a wonderful area!
3 May 2006. Meade SC 8″(!) + Atik NB + red filter 23a + barlow 2x. mosaic of 6 images.
The image above is one I have starkly enhanced to better show the delicate mare features - here is Jerome’s original version.
Yesterday's LPOD: Bird's Feet and Droppings?
Tomorrow's LPOD: An Elusive Phase