Asteroid resulted in the Cretaceous–Paleogene extinction, and the 1994 observation of Comet Shoemaker-Levy 9 crashing into Jupiter. The U.S. military also declassified the information that its military satellites, built to detect nuclear explosions, had detected hundreds of upper-atmosphere impacts by objects ranging from one to ten meters across. All these considerations helped spur the launch of highly efficient surveys that consist of charge-coupled device (CCD) cameras and computers directly connected to telescopes. , it was estimated that 89% to 96% of near-Earth asteroids one kilometer or larger in diameter had been discovered. A list of teams using such systems includes: ,
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