| Coordinates: | -16.3°N -17.5°W |
| Diameter: | 48 km |
| Colong: | 17 |
| Eponym: | Friedrich W. Opelt and Otto Moritz Opelt |
Opelt is the lava-flooded remnant of a lunar impact crater on the Mare Nubium. It lies to the north of a similar formation named Gould and to the northeast of the prominent Bullialdus.The crater was named after the German astronomers Friedrich Wilhelm Opelt and his son Otto Moritz Opelt.[1]
Only a slightly raised outline remains of Opelt's rim, the interior having been inundated with lava. The rim has a wide break at the northern end and several smaller breaks to the south and southeast. The satellite crater Opelt E lies at the southern end of the surviving western rim. The interior floor is nearly level, with the exception of a slight rise to the southwest, which is continuous with a wrinkle ridge to the south.
To the north of Opelt on the lunar mare is a sinuous system of rilles designated Rimae Opelt. These occupy a diameter of about 70 kilometers.
By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Opelt.
| Opelt | Latitude | Longitude | Diameter | |
|---|---|---|---|---|
| E | 17.0° S | 17.8° W | 8 km | |
| F | 18.1° S | 18.7° W | 4 km | |
| G | 16.8° S | 17.2° W | 4 km | |
| H | 15.8° S | 17.3° W | 3 km | |
| K | 13.6° S | 17.1° W | 5 km |
. Patrick Moore . 2001 . On the Moon . . 978-0-304-35469-6 .
. Antonín Rükl . 1990 . Atlas of the Moon . . 978-0-913135-17-4 .
. Thomas William Webb . 1962 . Celestial Objects for Common Telescopes . 6th revised . Dover . 978-0-486-20917-3 .
. Ewen Whitaker . 1999 . Mapping and Naming the Moon . Cambridge University Press . 978-0-521-62248-6 .