Oort Cloud: The Oort Cloud is the name given to a cloud of icy bodies which may orbit the Sun. The existence of the Oort Cloud has not been proven. The cloud is thought to be spherical and to surround the solar system. It may stretch from the end of the Kuiper Belt halfway to the nearest star. Scientists estimate that the Oort Cloud extends 100,000 AU from the Sun. The objects in the Oort Cloud are at the outer limit of the Sun's gravitational pull. It is named after Jan Oort, the Dutch astronomer who first spoke of its existence in 1950. The Oort Cloud may be the remains of the nebula that formed the solar system.
