The outer rim of Alter has been degraded by subsequent erosion, most notably at the northern and southern extremes. There is a small crater lying across the south-southeast rim. A cleft runs across the floor from the southern rim toward the north-northeast.
Ray material cross the crater floor from the east, forming a pair of faint bands.
Satellite craters
By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Alter.
Alter
Latitude
Longitude
Diameter
K
16.3° N
106.0° W
22 km
W
20.4° N
109.2° W
52 km
References
Andersson, L. E.;
Whitaker, E. A. (1982). NASA Catalogue of Lunar Nomenclature. NASA RP-1097.
Menzel, D. H.; Minnaert, M.; Levin, B.; Dollfus, A.; Bell, B. (1971). "Report on Lunar Nomenclature by the Working Group of Commission 17 of the IAU". Space Science Reviews. 12 (2): 136–186.
Bibcode:
1971SSRv...12..136M.
doi:
10.1007/BF00171763.
S2CID122125855.