Geological Chronicle
Positioned on the rugged far side of the Moon, Ibn Firnas spans 88.29 kilometers across and displays the battered morphology typical of an ancient impact structure. The crater sits in close proximity to major landmarks, directly adjoining the exterior southwest wall of the prominent crater King. Just a few kilometers to the north, separated only by an uneven stretch of highlands, lies the larger impact crater Ostwald. These neighboring formations have directly shaped the rim and interior margins of Ibn Firnas over geologic time.
The physical structure of Ibn Firnas reflects prolonged degradation, featuring worn and rounded rims marked by smaller impacts along its northern and eastern crests. Its interior floor is distinctly irregular along the northern and southwestern sections, where the violent formation of Ostwald and King disturbed the terrain. Smaller impacts also intrude into the basin; the satellite crater Ibn Firnas L rests on the southeastern inner wall and spreads onto the floor, while the bowl-shaped crater Melissa, originally designated Ibn Firnas Y, cuts through the northern rim.
Before receiving its formal name from the International Astronomical Union, lunar cartographers designated the feature as Crater 213. In 1976, the IAU officially renamed the basin in honor of Abbas Ibn Firnas, a ninth-century Andalusian polymath who constructed astronomical rings to simulate planetary motions. Detailed mapping of the crater and its adjoining highlands was subsequently codified on Lunar Topographic Orthophotomaps such as LTO-65C1.