Gemma Frisius is a lunar impact crater that is located in the rugged southern highlands of the Moon. It was named after Dutch physician Gemma Frisius. It lies to the north of the walled plain called Maurolycus, and southeast of the smaller crater Poisson. The crater Goodacre is attached to the northeast rim.

The outer wall of this crater has been heavily damaged by impacts, particularly along the north and west sides. The smaller satellite craters D, G, and H are attached to this damaged crater. As some observers have noted, this crater formation bears a certain resemblance to a paw print with these craters forming three of the toes and the crater Goodacre the fourth.

The southeastern rim of the crater is also worn, and the inner wall has slumped nearly a third of the distance across the interior floor. The remainder of the floor is relatively level and deep, with a central peak that is offset to the northwest of the midpoint.

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 Gemma Frisius.

GemmaFrisius LatitudeLongitudeDiameterA35.8° S15.2° E68 kmB35.5° S17.1° E41 kmC35.6° S18.8° E35 kmD34.3° S10.9° E28 kmE37.2° S12.8° E19 kmF35.8° S10.3° E9 kmG33.2° S11.4° E37 kmH32.4° S12.2° E28 kmJ35.1° S18.1° E12 kmK37.4° S11.0° E10 kmL34.8° S11.8° E6 kmM34.3° S12.5° E5 kmO32.5° S12.9° E6 kmP31.8° S12.8° E4 kmQ35.8° S14.8° E9 kmR37.1° S15.3° E5 kmS35.2° S15.1° E6 kmT34.9° S16.4° E8 kmU34.5° S16.8° E8 kmW36.9° S13.3° E15 kmX34.7° S15.8° E15 kmY37.4° S13.5° E28 kmZ35.1° S9.6° E10 km

References