Comet Shoemaker–Levy 9 rarity: one post-impact study estimated that comets in diameter impact the planet once in approximately 500 years and those in diameter do so just once in every 6,000 years. There is very strong evidence that comets have previously been fragmented and collided with Jupiter and its satellites. During the Voyager missions to the planet, planetary scientists identified 13 crater chains on Callisto and three on Ganymede, the origin of which was initially a mystery. Crater chains seen on the Moon often radiate from large craters, and are thought to be caused by secondary impacts of the original ejecta, but the
The Elves and the Shoemaker cartoon short "Holiday for Shoestrings". In the "Due South" episode, "The Deal", Det. Ray Vecchio vaguely recollects this story when discussing a poor cobbler with his partner, Constable Fraser. In "", a spinoff miniseries of the Vertigo comic-book series "Fables", the shoemaker appears as an employee in Cinderella's shoe store, while the elves are the builders and suppliers of the store's inventory. "Muppet Classic Theater" had a version where a shoemaker (played by Kermit the Frog) faces ruin until his livelihood is saved by a group of philanthropic entertainers (played by The Elvises) who, naturally, make only blue suede shoes.