August 28, 2022
On this date in 1789, William Herschel discovered Saturn’s sixth largest moon Enceladus. Herschel used his famous “Great Forty-Foot” telescope – with a 48 in diameter – for the initial discovery, and it wasn’t until the Voyager missions that humans were able to get a more detailed look at Enceladus. Voyager 2 provided the first images of surface details, including heavily cratered regions, distinct smooth regions, and large cracks and scarps in the icy crust.
A sketch from 1789 of the reflector telescope that Herschel used to discover both the 6th and 7th moons of Saturn – Enceladus and Mimas respectively. Image credit: public domain, scan of Leisure Hour, Nov 2,1867, page 729