Ibn Firnas (crater)

Ibn Firnas is a lunar impact crater on the far side of the Moon. Attached to the exterior of its southwestern rim is the prominent crater King. Only a few kilometers to the north, separated by a rugged stretch of terrain, is the larger crater Ostwald.

Ibn Firnas is a worn and eroded crater with small impacts along the northern and eastern rims. The satellite crater Ibn Firnas L lies along the inner wall to the southeast and covers part of the interior floor. Along the northern side, the small satellite crater Ibn Firnas Y cuts through the rim and overlays part of the inner wall. The interior floor is irregular along the northern and southwest sections where their shape has been modified by the large nearby craters mentioned above. Several small craters lie across the remainder of the interior floor.

In 1976 the crater was named by the IAU after Abbas Ibn Firnas, a polymath from Andalucia who, in the 9th century, devised a chain of rings that could be used to simulate the motions of the planets and stars. Prior to 1976, this crater was known as Crater 213.