title: Opelt (crater)
text: # Opelt (crater)
  
  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.
  
  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.
  
  ## 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 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 |
  