April 3, 2008
image by Stefan Lammel, Uxbridge, England
Yesterday's LPOD was a low angle, sunrise view of the northern corner of Mare Tranquillitatis that revealed variations in surface textures. Today's view by Stefan of the same area, part of a wonderful high resolution mosaic of most of Tranquillitatis, provides a complementary look, this time at small scale features. There are a number of features I have never noticed before, including that the continuation of the rille that is covered by Dawes and its ejecta is just visible at the edge of the mare at the right near Fabbroni. Suggestion of a linear fault comes from the very straight boundary south of Vitruvius. When I first noticed that the mare juts up against the rugged highlands I thought an error must have been made in mosaicking. But no, Stefan knows what he is doing; the straight edge is real and seems to generally align with the northern end of the Cauchy Rille - I wonder why? Another peculiar type of feature shown here is the lava-filled or lava-draped craters. The most obvious one is Jansen R, the large ring just north of and about the same size as Jansen. Is that what Jansen would look like if it were mostly buried by mare lavas? Two other smaller craters that may have a similar history of mare inundation are the one just under R, and Plinius B, between Plinius and Jansen. These look weird but may have originally been just like the nearby fresh impact craters Jansen E and F. Finally, note the domes visible even in high Sun at the left margin of the image, and the isolated, pit-topped dome in the bottom left quadrant. This area repays lots of study!
Feb 12, 2008. 10in f4.8 Newtonian, Infinity 2-1M, 4x PowerMate, green filter, 1100/2-3000, MAP: 42x64, Registax, PSE 5, Focus Magic
Rükl plates 24, 25, 35 & 36
Yesterday's LPOD: Color And Morphology
Tomorrow's LPOD: Psychological Insight or Lunacy?
Dave Storey:- This is a fascinating area and definitely is on my list for looking at in the near future. Can't believe I have not noticed what this area of the moon has to offer. Thanks Stefan for uploading your great images to the web and LPOD and Chuck for zooming in on the above image from the original Mare Tranquillitatisby Stefan.