Diophantus is a small lunar impact crater that lies in the southwestern part of the Mare Imbrium. It forms a pair with the larger crater Delisle to the north. At a similar distance to the west is the smaller Artsimovich crater and the Fedorov feature.
On the lunar geologic timescale, Diophantus is a crater of Eratosthenian age. It is a sharp-edged crater with a wide inner wall and a low central rise. It shows no degradation from subsequent impacts. High resolution imagery of the inner wall show dark streaks, which originate from material exposed by the impact. A skirt of ejecta spreads across the surrounding mare surface. The cup-shaped impact crater Diophantus C lies prominently near the exterior of the southwest wall.
To the north of Diophantus is the sinuous rille designated Rima Diophantus, named after the crater. It is centered at selenographic coordinates , and has a maximum diameter of . This cleft follows a generally east–west path across the Mare Imbrium. The section nearest Diophantus crater is partially filled with ejecta from that impact.
This formation named after the ancient Greek mathematician Diophantus (unkn-c. A.D. 300). His name was included in the lunar nomenclature of German selenographer Johann H. von Mädler during the 19th century. Its designation was formally adopted by the International Astronomical Union in 1935.
Small craters
Several tiny craters north of Diophantus have been assigned names by the IAU. These are listed in the table below.
CraterCoordinatesDiameterName sourceIsabel1 kmSpanish feminine nameLouise0.8 kmFrench feminine nameSamir2 kmArabic masculine nameWalter11 kmGerman masculine name
1Not to be confused with the large crater Walther in the southern hemisphere, which is misidentified as 'Walter' in some publications
The crater Samir has bright rays that extend for over 70 km.
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 Diophantus.
DiophantusLatitudeLongitudeDiameterB29.1° N32.5° W6 kmC27.3° N34.7° W5 kmD26.9° N36.3° W4 km
The following crater has been renamed by the IAU.
Diophantus A — See Artsimovich.
Gallery
References
Sources
External links
LTO-39B3 Diophantus — L&PI topographic map of crater and vicinity.