| Coordinates: | -51.6°N -35°W |
| Diameter: | 47 km |
| Depth: | 2.0 km |
| Colong: | 35 |
| Eponym: | Johann Bayer |
Bayer is a lunar impact crater located in the southwest section of the moon, to the east of the crater Schiller. The rim of Bayer is slightly worn by erosion, but remains well-defined. There is an inner terrace, but the outer wall is intruded upon by nearby impacts. The most significant of these is Schiller H, which forms a ridge attached to the northwest rim of Bayer. The floor of Bayer is relatively flat and lacks a central peak. There is a small, but notable crater on the floor near the western wall. This crater has a breach in its northern rim.
By convention these features are identified on Lunar maps by placing the letter on the side of the crater midpoint that is closest to Bayer.
| Bayer | Latitude | Longitude | Diameter | |
|---|---|---|---|---|
| A | 51.3° S | 30.3° W | 18 km | |
| B | 48.8° S | 28.2° W | 18 km | |
| C | 49.7° S | 31.2° W | 22 km | |
| D | 47.9° S | 29.8° W | 20 km | |
| E | 51.7° S | 32.3° W | 29 km | |
| F | 53.0° S | 31.6° W | 20 km | |
| G | 51.7° S | 35.3° W | 7 km | |
| H | 53.5° S | 32.5° W | 27 km | |
| J | 52.5° S | 33.6° W | 18 km | |
| K | 50.2° S | 34.0° W | 16 km | |
| L | 47.5° S | 33.6° W | 14 km | |
| M | 50.6° S | 31.0° W | 10 km | |
| N | 48.3° S | 29.2° W | 9 km | |
| P | 51.6° S | 29.5° W | 4 km | |
| R | 52.5° S | 35.5° W | 9 km | |
| S | 52.3° S | 36.4° W | 13 km | |
| T | 49.2° S | 30.1° W | 8 km | |
| U | 48.4° S | 31.3° W | 10 km | |
| V | 47.5° S | 31.6° W | 9 km | |
| W | 48.0° S | 33.5° W | 9 km | |
| X | 53.4° S | 33.6° W | 8 km | |
| Y | 49.2° S | 35.7° W | 31 km | |
| Z | 49.0° S | 33.4° W | 7 km |