This episode starts on the subject of the Galilean moons of Jupiter Io, Europa, Callisto, and Ganymede, which were confirmed by Galileo to be moons in 1610, and somehow ends up on The Holy Island of Lindisfarne, an island off the coast of England that was an important center of Celtic Christianity and nowadays is a National Nature Reserve as well as an Area of Outstanding Beauty. How are they connected? You’ll have to listen to find out.