October 18, 2018
Originally published August 4, 2009
image by Stefan Lammel
Sheet E7 of the System of Lunar Craters includes the last official designations for the Ramsden rilles. Like de Gasparis and Palmieri, Ramsden is a focal point for small linear rilles, but in this case the rilles cut the rim but do not appear to cross its floor. The rilles drawn in E7 are easy to match with the better detail that we now have with Stefan's image, and an addition rille is distinct enough that I have added the number VII to. I thought that because this rille extends near Mercator that perhaps it should be numbered for that crater, but finally decided that adding it to the Ramsden system made more sense because it may be structurally related. But its curvature is also consistent with that of the Hippalus rilles to the north - this just illustrates that often nomenclature decisions have to be made without as much geologic understanding as is desirable.
Jan 6, 2009, 2200 UT. 10in f4.8 Newtonian, Infinity 2-1M, 5x Powermate, green filter, Avistack, Registax v.5, PSE5, Focus Magic
Rükl plate 63
See Stefan's entire mosaic
An interpretation of the origin of the Ramsden rilles.
Yesterday's LPOD: Slip Sliding Away
Tomorrow's LPOD: Tourist Moon