Comet Shoemaker–Levy 9 and well within the orbit of Jupiter's innermost moon Metis and the planet's Roche limit, inside which tidal forces are strong enough to disrupt a body held together only by gravity. Although the comet had approached Jupiter closely before, the July 7 encounter seemed to be by far the closest, and the fragmentation of the comet is thought to have occurred at this time. Each fragment of the comet was denoted by a letter of the alphabet, from "fragment A" through to "fragment W", a practice already established from previously observed broken-up comets. More exciting for planetary astronomers was that
Herschel Space Observatory had been delivered as a result of the collision of Comet Shoemaker–Levy 9 in 1994. On 22 January 2014, ESA scientists reported the detection, for the first definitive time, of water vapor on the dwarf planet, Ceres, largest object in the asteroid belt. The detection was made by using the far-infrared abilities of the "Herschel Space Observatory". The finding is unexpected because comets, not asteroids, are typically considered to "sprout jets and plumes". According to one of the scientists, "The lines are becoming more and more blurred between comets and asteroids." On 29 April 2013, ESA announced that "Herschel" supply