Comet Shoemaker–Levy 9 the Cretaceous period is generally thought to have been caused by the Cretaceous–Paleogene impact event, which created the Chicxulub crater, demonstrating that impacts are a serious threat to life on Earth. Astronomers have speculated that without Jupiter to mop up potential impactors, extinction events might have been more frequent on Earth, and complex life might not have been able to develop. This is part of the argument used in the Rare Earth hypothesis. In 2009, it was shown that the presence of a smaller planet at Jupiter's position in the Solar System might increase the impact rate of comets on
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