Lost comet Comet Shoemaker–Levy 9, which collided with Jupiter in 1994. Lost comet A comet is "lost" when it has been missed at its most recent perihelion passage. This generally happens when data is insufficient to reliably calculate the comet's orbit and predict its location. The "D/" designation is used for a periodic comet that no longer exists or is deemed to have disappeared. Lost comets can be compared to lost minor planets, although calculation of comet orbits differs because of nongravitational forces, such as emission of jets of gas from the nucleus. Some astronomers have specialized in this area, such as
The Elves and the Shoemaker The Elves and the Shoemaker "The Elves and the Shoemaker" is an often copied and re-made 1806 story about a poor shoemaker who receives much-needed help from elves. The original story is the first of three fairy tales, contained as entry 39 in the German "Grimm's Fairy Tales" under the common title "Die Wichtelmänner". In her translation of 1884 Margaret Hunt chose The Elves as title for these three stories. The Aarne–Thompson folklore classification system categorizes the story as type 503*: Helpful Elves and also as a migratory legend, type 7015. There are variations depending on the rendition of the