Herschel Discovers Saturn’s Death Star Moon, Mimas, in 1789

On Sept. 17, 1789, William Herschel first spotted Saturn’s small moon Mimas, whose prominent Herschel crater gives it the “Death Star” likeness; at about 395 km across, Mimas is Saturn’s inner major moon and completes an orbit every ~22 hours in a tidally locked arrangement, with Voyager 1/2 and Cassini imagery revealing its cratered, icy surface. The piece also notes NASA’s 1976 naming of the space shuttle Enterprise on Sept. 17.