Craters Dionysius Origin of the name St. Dionysius the Areopagite; Greek astronomer (fl. 1st century A.D.). When to observe it … Nearby Rimae Ritter 30 km Ariadaeus 54 km Ritter 62 km Schmidt 71 km De Morgan 75 km Cayley 75 km D'Arrest 83 km Sabine 94 km