1. Oort Cloud - Noun
2. Oort Cloud - Proper noun
(astronomy) a hypothetical huge collection of comets orbiting the sun far beyond the orbit of Pluto; perturbations (as by other stars) can upset a comet's orbit and may send it tumbling toward the sun
Source: WordNetAccording to the models, about half of the objects scattered travel outward toward the Oort cloud, whereas a quarter are shifted inward to Jupiter's orbit, and a quarter are ejected on hyperbolic orbits. Source: Internet
According to these models, the number of collisions early in the Solar System's history was so great that most comets were destroyed before they reached the Oort cloud. Source: Internet
Although no confirmed direct observations of the Oort cloud have been made, it may be the source of all long-period and Halley-type comets entering the inner Solar System, and many of the centaurs and Jupiter -family comets as well. Source: Internet
Galactic tidal forces stretch the cloud along an axis directed toward the galactic centre and compress it along the other two axes; these small perturbations can shift orbits in the Oort cloud to bring objects close to the Sun. Source: Internet
Based on their orbits, most of the short-period comets may come from the scattered disc, but some may still have originated from the Oort cloud. Source: Internet
Davies p. 39 For an Oort cloud object to become a short-period comet, it would first have to be captured by the giant planets. Source: Internet