LPOD Feb 8, 2008

HUMOR ME ONCE MORE

image by Rafael Benavides, Posadas, Córdoba, Spain

I never realized how rille infested the Humorum area is. Yesterday's image by Rafael featured the massive Hippalus Rilles and smaller Ramsden Rilles on the east and southeast edges of Mare Humorum, and today I follow Rafael to the southwest of Humorum. Here the rilles are small - looking very much in size and character like those near Ramsden. Palmieri and de Gasparis (G) have rille-crossings, and 2-3 very narrow rilles continue south where the Liebig Scarp (LS) comes onshore. The straight Doppelmayer Rille (DR) was the source of dark pyroclastic material that mantles its sides (see at high Sun). All of these rilles are associated with some sort of volcanism, including the hints of rilles in the floor-fractured crater Doppelmayer. Another sign of volcanism is the apparent dome (arrow) on the dark floor of an old crater between Liebig (L) and Palmieri. This feature does not appear on the GRL Dome Chart but I am sure it is known. The tiny crater on its flank has a very bright tiny ray pattern at full Moon. Another, steeper-sided hill is just to the east of the Doppelmayer Rille. This is in the wrong place to be the central peak or a piece of the rim of the old crater the Doppelmayer Rille crosses. But its in the right place to cause us to wonder.

Chuck Wood

Technical Details
Jan 19, 2008, 20:12 UT. Celestron 11 + Barlow 2X + IR pass filter + Luna-QHY 5 mono camera.

Related Links
Rükl plates 51 & 52
Rafael's website

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