| Diameter | 40 km |
|---|---|
| Depth | 3.4 km |
| Colongitude | 44° at sunrise |
| Eponym | Jean J. d'Ortous de Mairan |
Mairan is a lunar impact crater that is located on a highland peninsula between Oceanus Procellarum to the west and Mare Imbrium to the east. To the north-northeast is the comparably sized crater Sharp. Northwest of Mairan is the heavily eroded Louville.
The outer rim of Mairan has not been significantly eroded or impacted, and retains a sharp edge. The surface around Mairan is rough and irregular, with a multitude of many tiny craters, particularly to the south and west. The inner walls display some terracing, and flow down to a relatively flat interior floor.
In the mare due west of Mairan is a small lunar dome designated Mairan T. The dome has a tiny crater at the summit. There is also a sinuous rille along the southwest edge of the highland peninsula containing Mairan. It is designated Rima Mairan, and follows a north–south course for a length of about 100 kilometers.
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 Mairan.
| Mairan | Latitude | Longitude | Diameter |
|---|---|---|---|
| A | 38.6° N | 38.8° W | 16 km |
| C | 38.6° N | 46.0° W | 7 km |
| D | 40.9° N | 45.4° W | 10 km |
| E | 37.8° N | 37.2° W | 6 km |
| F | 40.3° N | 45.1° W | 9 km |
| G | 40.9° N | 50.8° W | 6 km |
| H | 39.3° N | 40.0° W | 5 km |
| K | 40.8° N | 41.0° W | 6 km |
| L | 39.0° N | 43.2° W | 6 km |
| N | 39.2° N | 45.5° W | 6 km |
| T | 41.7° N | 48.3° W | 3 km |
| Y | 42.7° N | 44.0° W | 7 km |