Hahn

D=88 km
Center: 31°N, 74°E

Count Area: 671 km^2
Observed Density (@ 1km): 16400 ± 5000
Age: 3.8 ± 0.1 (+sec: 3.8)
Stoffler epoch:  Early Imbrian
Fit density (@ 1km): 17300 ± 1100
PF fit: good, some small craters slightly shallow, area < 1000 km2

Age calculation notes:
good fit (SM).
OK fit - 1 point slightly off at small end - use as is; adding OSs slightly improves fit (moves 1 point to curve), but does not change age (MRK).

USGS geology: 
Crater mapped as mid-Imbrian crater material, but southern part of crater mapped as Late Imbrian fill, which is section counted.

Wilhelms: 
Early Imbrian

Floor material: 
Best guess is not original. Smooth material (with a few hills - may indicate fill not thick?). Surrounded by other craters filled with mare. But not much evidence for embayment. Material looks softened. Soft?

Geology Observations: 
Ejecta blanket visible, looks somewhat eroded. Rim looks slightly eroded. Moderate size central peak. Floor terrain different between north and south. North part of crater more hummocky, with small dark smooth areas. South is smoother with some small hills. The northern half likely affected by large Eratosthenian-aged crater on rim. Secondary chains/clusters with small craters (up to ~ 900 m) - both degraded and fresh. 

SFD Observations: 
Dominated by classes 3 & 4. Few fresh craters. Distribution < 1.5 km shallower than others for this size range. Distribution rather flat overall. Slope(Diff)=2.8 ± 0.5. This is one of those craters with an unusual distribution.

Discussion notes: 
change to "possibly" original floor. not a good strength candidate.

Last Edited by MRK 12/13/2012