Römer ( crater ) Crater characteristics Coordinates 25.4° N , 36.4° E Diameter 40 km Depth 3.3 km Colongitude    324° at sunrise Eponym Ole Rømer Römer is a lunar impact crater that is located to the north of the Sinus Amoris in the northeast section of the Moon . It lies in the southwest part of the mountainous region named the Montes Taurus . To the west-northwest is the crater-bay Le Monier , on the east edge of Mare Serenitatis . The rim of Römer has relatively high walls with a terraced inner surface . There is a small craterlet on the north part of the floor , and a large central peak at the mid-point . To the northwest of the crater is a prominent system of rilles named the Rimae Römer . These follow a course to the north from the west rim of the crater , and have a combined length of about 110 kilometres . Satellite craters By convention these features are identified on lunar maps by placing the letter on the side of the crater mid-point that is closest to Römer crater . Römer Latitude Longitude Diameter A 28.1° N 37.1° E 35 km B 28.6° N 38.2° E 20 km C 27.7° N 37.0° E 8 km D 24.5° N 35.8° E 13 km E 28.5° N 39.2° E 31 km F 27.1° N 37.2° E 22 km G 26.8° N 36.2° E 14 km H 25.9° N 35.7° E 6 km J 22.4° N 37.9° E 8 km M 25.3° N 34.6° E 10 km N 25.3° N 38.0° E 26 km P 26.5° N 39.6° E 61 km R 24.2° N 34.6° E 42 km S 24.9° N 36.8° E 44 km T 23.6° N 36.1° E 47 km U 24.3° N 39.1° E 28 km V 24.5° N 38.6° E 28 km W 26.4° N 40.4° E 7 km X 24.3° N 40.1° E 22 km Y 25.7° N 36.3° E 7 km Z 24.1° N 36.9° E 12 km The following craters have been renamed by the IAU . Römer K — See Franck crater . Römer L — See Brewster crater . Römer A is unofficially named Stephanides crater , after Greek scientist and poet Theodore Stephanides . References See the reference table for the general listing of literature and web sites that were used in the compilation of this page . Categories : Craters on the Moon 25.4 N 36.4 E 40 km 3.3 km 324 Ole Rømer 