Alphonsus_IR_0021 12-04-13 03-29-31_PSE_R

Alphonsus (119 km) has a single central peak that rises to 1.5 km above the crater's floor. The floor is criss-crossed by a system of rilles, some of which can be seen in this image. The most apparent run north-south on the east side. One of the most interesting features of this crater is that several of the small craterlets are encircled by dark patches up to 10 km in diameter which may be of volcanic origin, though this is not certain. Ranger 9 (crash) landed ~15 km north-east of the central mountain in 1965.
Waning Moon, 53% full
13 Apr 2012, 03:29 UT