Explanation:

Perhaps we need a double Valentine to ward off a Friday the 13th! The image on the left might seem familiar to long time visitors - it was LPOD in February, and was taken by KC Pau. The lower sun image on the right was acquired recently by Jim Phillips. These two images provide interesting complimentary and complementary (!) information. KC's beautifully shows the curving feature that cuts the dome and extends onto the mare. Jim's image shows it casting a shadow - it seems to be a fault rather than a rille! The lower lighting of Jim's image delineates the edge of the dome on all 4 sides - it doesn't slope down (tilt) imperceptibly to the mare surface as it appeared with the higher sun lighting. And the low lighting also shows that the dome is right on a mare ridge, in fact, perhaps at the intersection of two of them. Geologists love to find features at the intersection of tectonic structures because the double disruption of the crust suggests that it may be fractured and thus allow magma to rise to the surface. Finally, note the steeper-sided domical feature to the northeast of Valentine - is this another dome?

— Chuck Wood

Technical Details:
Pau image obtained 16 September 2003 at 21:11 UT using a 10" f/6 Newtonian and a webcam. Phillips image taken 10:23-10:26 UT on Aug 7, 2004 with TMB 8" F/9, 3X Barlow, Toucam Pro & Registax-700 images stacked.
CAW used unsharp mask on both images and rotated Jim's to match the orientation of KC's. North is to the upper right.

Related Links:
A study about the Valentine dome
Rukl, Atlas of the Moon, Section 13.

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